CN104734531A - Frequency converter - Google Patents
Frequency converter Download PDFInfo
- Publication number
- CN104734531A CN104734531A CN201310728104.XA CN201310728104A CN104734531A CN 104734531 A CN104734531 A CN 104734531A CN 201310728104 A CN201310728104 A CN 201310728104A CN 104734531 A CN104734531 A CN 104734531A
- Authority
- CN
- China
- Prior art keywords
- transistor
- winding
- circuit
- frequency converter
- electrically connected
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Inverter Devices (AREA)
- Rectifiers (AREA)
Abstract
The invention provides a frequency converter which comprises a rectifying circuit, a power factor correction circuit and an inverter circuit. The rectifying circuit, the power factor correction circuit and the inverter circuit are sequentially connected. One end of the rectifying circuit is electrically connected with an alternating-current power source, and the inverter circuit is electrically connected with a load. The power factor correction circuit comprises a first inductor L2 and a first transistor Z1. The first inductor comprises a first winding N1 and a second winding N2, and the first winding N1 and the second winding N2 are connected in series. A dotted terminal of the second winding N2 is electrically connected with a collector of the first transistor Z1, a tap of the first inductor L2 is coupled to the inverter circuit, and an undotted terminal of the first winding N1 is coupled to the rectifying circuit. An emitter of the first transistor Z1 is coupled to the ground, and one end of the rectifying circuit is coupled to the ground. According to the frequency converter, the voltage of a direct-current bus is reduced, and therefore the loss of the transistor is lowered, and the frequency converter saves electric energy.
Description
Technical field
The present invention relates to converter technology field, particularly relate to a kind of energy-conservation frequency converter.
Background technology
If Fig. 1 is the frequency converter of prior art, frequent switch motion is there is in transistor Z2 ~ Z7 that the work characteristics of himself determines wherein when high-voltage great-current, this produces larger on-state loss and switching loss by causing transistor, thus reduces the inversion efficiency of inverter circuit.Wherein, the inversion efficiency of inverter circuit is the power output of inverter circuit and the ratio of input power.Meanwhile, transistor Z2 ~ Z7 is frequent switch motion when high-voltage great-current, and the working temperature that result in transistor is higher, and the reliability of transistor is reduced; For this reason, need specialized designs heat abstractor, cost is higher.
Summary of the invention
In view of the present situation of prior art, the object of the present invention is to provide a kind of frequency converter, the DC bus-bar voltage of inverter circuit is reduced, thus realize the transformation of loud-break switch to low-voltage, high-current switch of transistor in inverter circuit, reduce on-state loss and the switching loss of transistor in inverter circuit.
For achieving the above object, the present invention adopts following technical scheme:
A kind of frequency converter, comprise rectification circuit, power factor correction circuit and inverter circuit, described rectification circuit, described power factor correction circuit are connected successively with described inverter circuit, and one end of described rectification circuit is electrically connected with AC power, and described inverter circuit is electrically connected with load;
Described power factor correction circuit comprises the first inductance L 2 and the first transistor Z1;
Described first inductance comprises the first winding N1 and the second winding N2, and described first winding N1 connects with described second winding N2;
The Same Name of Ends of described second winding N2 is electrically connected with the collector electrode of the first transistor Z1, and the tap coupler of described first inductance L 2 is to inverter circuit, and the different name end of described first winding N1 is coupled to described rectification circuit;
The emitter-coupled of described the first transistor Z1 is to ground, and the coupled one end of described rectification circuit is to ground.
Wherein in an embodiment, described power factor correction circuit also comprises the second inductance L 1, first diode D1, the second diode D2 and electric capacity C1;
The coupled one end of described second inductance L 1 is to described rectification circuit, and the other end of described second inductance L 1 connects the anode of described first diode D1 and described second diode D2;
The negative electrode of described first diode D1 is electrically connected with the Same Name of Ends of described second winding N2, and the negative electrode of described second diode is electrically connected with the different name end of described first winding;
One end of described electric capacity C1 connects the negative electrode of the second diode D2 and the different name end of described first winding N1, and the other end of described electric capacity is coupled to ground.
Wherein in an embodiment, described electric capacity C1 is electrochemical capacitor;
The positive pole of described electric capacity C1 connects the negative electrode of the second diode D2 and the different name end of described first winding N1, and the negative couplings of described electric capacity C1 is to ground.
Wherein in an embodiment, described inverter circuit comprises six transistors, is respectively transistor seconds Z2, third transistor Z3, the 4th transistor Z4, the 5th transistor Z5, the 6th transistor Z6 and the 7th transistor Z7;
The collector electrode of described transistor seconds Z2, described third transistor Z3 and described 4th transistor Z4 is all connected to the tap of described first inductance L 2;
The emitter of described transistor seconds Z2 is electrically connected with the collector electrode of described 5th transistor Z5, the emitter of described third transistor Z3 is electrically connected with the collector electrode of described 6th transistor Z6, and the emitter of described 4th transistor Z4 is electrically connected with the collector electrode of described 7th transistor Z7;
The emitter-coupled of described 5th transistor Z5, described 6th transistor Z6 and described 7th transistor Z7 is to ground.
Wherein in an embodiment, described the first transistor Z1 to described 7th transistor Z7 is npn type bipolar transistor.
Wherein in an embodiment, described load is motor, and the three-phase of described motor is connected to the emitter of described transistor seconds Z2 respectively, the emitter of described third transistor Z3 and the emitter of described 4th transistor Z4.
Wherein in an embodiment, described rectification circuit is rectifier bridge.
The invention has the beneficial effects as follows:
Frequency converter of the present invention, the upper brachium pontis of the DC bus of inverter circuit is from the middle power taking of the first inductance, before the switch motion of the transistor in inverter circuit, first control the first transistor conducting, thus reduce the voltage of DC bus, achieve the high-voltage large current switch of transistor in inverter circuit to low-voltage, high-current switch, thus reduce on-state loss and the switching loss of transistor, make this frequency converter save electric energy.Meanwhile, this frequency converter achieves the function of Active PFC and the function of DC bus-bar voltage adjustment.
Accompanying drawing explanation
Fig. 1 is the circuit theory diagrams of the frequency converter of prior art;
Fig. 2 is the circuit theory diagrams of an embodiment of frequency converter of the present invention.
Embodiment
In order to make technical scheme of the present invention clearly, below in conjunction with accompanying drawing, frequency converter of the present invention is described in further detail.Should be appreciated that specific embodiment described herein only in order to explain that the present invention is not intended to limit the present invention.
Be illustrated in figure 2 the circuit theory diagrams of an embodiment of frequency converter of the present invention, this frequency converter comprises rectification circuit, power factor correction circuit and inverter circuit.Wherein, one end of rectification circuit is electrically connected with AC power, and rectification circuit is electrically connected successively with power factor correction circuit and inverter circuit, and inverter circuit is electrically connected with load.Preferably, this rectification circuit is rectifier bridge, and this rectifier bridge DB1 is made up of, for AC power is converted into DC power supply four diodes.
Power factor correction circuit comprises the first inductance L 2 and the first transistor Z1.First inductance L 2 comprises the first winding N1 and the second winding N2, and the first winding N1 connects with the second winding N2.It should be understood that series connection herein refers to that the Same Name of Ends of the first winding N1 is connected with the different name end of the second winding N2.
The Same Name of Ends of the second winding N2 is electrically connected with the collector electrode of the first transistor Z1, and the tap coupler of the first inductance L 2 is to inverter circuit, and the different name end of the first winding N1 is coupled to rectification circuit.The emitter-coupled of the first transistor Z1 is to ground.Preferably, the first transistor Z1 is npn type bipolar transistor.
Preferably, inverter circuit is three-phase inverting circuit.The collector electrode of transistor seconds Z2, third transistor Z3 and the 4th transistor Z4 is all connected to the tap of the first inductance L 2, and namely the collector electrode of transistor seconds Z2, third transistor Z3 and the 4th transistor Z4 is all connected to the Same Name of Ends of the first winding N1.The emitter-coupled of the 5th transistor Z5, the 6th transistor Z6 and the 7th transistor Z7 is to ground.
The emitter of transistor seconds Z2 is electrically connected with the collector electrode of the 5th transistor Z5, and the base stage of transistor seconds Z2 connects the upper brachium pontis pwm control signal UP of U phase, and the base stage of the 5th transistor Z5 connects the lower brachium pontis pwm control signal UN of U phase.The emitter of third transistor Z3 is electrically connected with the collector electrode of the 6th transistor Z6, and the base stage of third transistor Z3 connects the upper brachium pontis pwm control signal VP of V phase, and the base stage of the 6th transistor Z6 connects the lower brachium pontis pwm control signal VN of V phase.In like manner, the emitter of the 4th transistor Z4 is electrically connected with the collector electrode of the 7th transistor Z7, and the base stage of the 4th transistor Z4 connects the upper brachium pontis pwm control signal WP of W phase, and the base stage of the 7th transistor Z7 connects the lower brachium pontis pwm control signal WN of W phase.
Preferably, transistor seconds Z2 is npn type bipolar transistor to the 7th transistor Z7.In the present embodiment, load is motor.And the U of motor is connected to the emitter of transistor seconds Z2, the V of motor is connected to the emitter of third transistor Z3, and the W of motor is connected to the emitter of the 4th transistor Z4.
In inverter circuit transistor switch motion before, first control the first transistor conducting, the upper brachium pontis P pole of the DC bus of inverter circuit is from the middle power taking of the first inductance, reduce the voltage of the upper brachium pontis P pole of DC bus, achieve the transformation of high-voltage large current switch to low-voltage, high-current switch of transistor in inverter circuit, reduce on-state loss and the switching loss of transistor in inverter circuit, make the loss of this frequency converter reduce 30%, achieve the power saving function of frequency converter.
After the conducting of the first transistor Z1, then control the switch motion of the transistor Z2 ~ Z7 in inverter circuit, thus the upper brachium pontis P electrode drop of DC bus is low to moderate lower magnitude of voltage.In the present embodiment, the magnitude of voltage of the upper brachium pontis P pole of DC bus is according to N2/(N1+N2) value determine, and then control the switch state of transistor Z2 ~ Z7 according to the control overflow of motor.Namely in the present embodiment, the magnitude of voltage at the two ends of the second winding N2 is the magnitude of voltage of the upper brachium pontis P pole of DC bus, therefore, the position of the tap of tap inductor L2 can be regulated according to the control overflow of motor, and then realize the adjustment of magnitude of voltage of upper brachium pontis P pole of DC bus.
As a kind of embodiment, power factor correction circuit also comprises the second inductance L 1, first diode D1, the second diode D2 and electric capacity C1.Wherein, the coupled one end of the second inductance L 1 is to rectification circuit DB1, and the other end of the second inductance L 1 connects the anode of the first diode D1 and the second diode D2.The negative electrode of the first diode D1 is electrically connected with the Same Name of Ends of the second winding N2, and the negative electrode of the second diode D2 is electrically connected with the different name end of the first winding N1.One end of electric capacity C1 connects the negative electrode of the second diode D2 and the different name end of the first winding N1, and the other end of electric capacity is coupled to ground.
Wherein, the first diode D1 is for preventing current reflux in the first inductance L 2 to AC power, and the second diode D2 is for preventing current reflux on electric capacity C1 to AC power.Preferably, electric capacity C1 is electrochemical capacitor.And the positive pole of electric capacity C1 connects the negative electrode of the second diode D2 and the different name end of the first winding N1, the negative couplings of electric capacity C1 is to ground.
When the first transistor Z1 conducting, charge to the second inductance L 1 in the loop that AC power is formed by the first diode D1, the first transistor Z1 after rectification circuit DB1 rectification, the second inductance L 1 store electrical energy.Now carried out the exchange of energy by the charging and discharging between control second inductance L 1 and electric capacity C1, maintain the electromagnetic induction process of inductive load.Due in sinusoidal ac circuit, 90 °, the voltage delay electric current of capacitor, the voltage leading current of inductance 90 °, as long as therefore the capacitive reactance of electric capacity and the induction reactance of inductance are arranged in pairs or groups suitably, just can reach the phase place of voltage and current in electrical network identical, and AC power is unaffected, achieve the function of Active PFC.
It should be understood that power factor (PF) herein refers to the active power in the loop of system and the ratio of gross power, power factor (PF) can weigh the degree that electric power is used effectively.The value of power factor (PF) is larger, then the utilance of electric power is higher, but is the highlyest no more than 1.Active PFC is exactly forbid that the electric current (inductance current) of inductive load is back to electrical network, and the phase place of the voltage and current in electrical network will be kept all the time identical.
When the first transistor Z1 ends, AC power, by after rectification circuit DB1 rectification, is charged to electric capacity C1 by the second inductance L 1, second diode D2, electric capacity C1 store electrical energy.Now, the energy stored in the second inductance L 1 is charged by the second diode D2 electric capacity C1, and electric capacity C1 is powered by the upper brachium pontis P pole of the first inductance L 2 to DC bus, can realize the function that DC bus-bar voltage promotes.Like this when direct voltage is lower, do not need to increase extra DC/DC boost inverter, reduce the cost of transformer, simplify circuit structure.
When the load variations of inverter circuit, when the number of turn as the coil of motor changes, can take specific control strategy, this control strategy can be that to maintain Dead Time constant or change inverter circuit or change the mode etc. of switching frequency of the first transistor Z1.Keep power factor correction circuit to export constant voltage by above-mentioned specific control strategy, meet the requirement of Electric Machine Control.
Above-mentioned frequency converter, the upper brachium pontis of the DC bus of inverter circuit is from the middle power taking of the first inductance, before the switch motion of the transistor in inverter circuit, first control the first transistor conducting, thus reduce the voltage of DC bus, achieve the high-voltage large current switch of transistor in inverter circuit to low-voltage, high-current switch, thus reduce on-state loss and the switching loss of transistor, make this frequency converter save electric energy.Meanwhile, this frequency converter achieves the function of Active PFC and the function of DC bus-bar voltage adjustment.
The above embodiment only have expressed several execution mode of the present invention, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection range of patent of the present invention should be as the criterion with claims.
Claims (7)
1. a frequency converter, comprise rectification circuit, power factor correction circuit and inverter circuit, described rectification circuit, described power factor correction circuit are connected successively with described inverter circuit, one end of described rectification circuit is electrically connected with AC power, described inverter circuit is electrically connected with load, it is characterized in that:
Described power factor correction circuit comprises the first inductance L 2 and the first transistor Z1;
Described first inductance comprises the first winding N1 and the second winding N2, and described first winding N1 connects with described second winding N2;
The Same Name of Ends of described second winding N2 is electrically connected with the collector electrode of the first transistor Z1, and the tap coupler of described first inductance L 2 is to inverter circuit, and the different name end of described first winding N1 is coupled to described rectification circuit;
The emitter-coupled of described the first transistor Z1 is to ground, and the coupled one end of described rectification circuit is to ground.
2. frequency converter according to claim 1, is characterized in that:
Described power factor correction circuit also comprises the second inductance L 1, first diode D1, the second diode D2 and electric capacity C1;
The coupled one end of described second inductance L 1 is to described rectification circuit, and the other end of described second inductance L 1 connects the anode of described first diode D1 and described second diode D2;
The negative electrode of described first diode D1 is electrically connected with the Same Name of Ends of described second winding N2, and the negative electrode of described second diode D2 is electrically connected with the different name end of described first winding N1;
One end of described electric capacity C1 connects the negative electrode of described second diode D2 and the different name end of described first winding N1, and the other end of described electric capacity is coupled to ground.
3. frequency converter according to claim 2, is characterized in that:
Described electric capacity C1 is electrochemical capacitor;
The positive pole of described electric capacity C1 connects the negative electrode of described second diode D2 and the different name end of described first winding N1, and the negative couplings of described electric capacity C1 is to ground.
4. the frequency converter according to any one of claim 1-3, is characterized in that:
Described inverter circuit comprises six transistors, is respectively transistor seconds Z2, third transistor Z3, the 4th transistor Z4, the 5th transistor Z5, the 6th transistor Z6 and the 7th transistor Z7;
The collector electrode of described transistor seconds Z2, described third transistor Z3 and described 4th transistor Z4 is all connected to the tap of described first inductance L 2;
The emitter of described transistor seconds Z2 is electrically connected with the collector electrode of described 5th transistor Z5, the emitter of described third transistor Z3 is electrically connected with the collector electrode of described 6th transistor Z6, and the emitter of described 4th transistor Z4 is electrically connected with the collector electrode of described 7th transistor Z7;
The emitter-coupled of described 5th transistor Z5, described 6th transistor Z6 and described 7th transistor Z7 is to ground.
5. frequency converter according to claim 4, is characterized in that:
Described the first transistor Z1 to described 7th transistor Z7 is npn type bipolar transistor.
6. frequency converter according to claim 5, is characterized in that:
Described load is motor, and the three-phase of described motor is connected to the emitter of described transistor seconds Z2 respectively, the emitter of described third transistor Z3 and the emitter of described 4th transistor Z4.
7. frequency converter according to claim 6, is characterized in that:
Described rectification circuit is rectifier bridge.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310728104.XA CN104734531B (en) | 2013-12-24 | 2013-12-24 | Frequency converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310728104.XA CN104734531B (en) | 2013-12-24 | 2013-12-24 | Frequency converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104734531A true CN104734531A (en) | 2015-06-24 |
| CN104734531B CN104734531B (en) | 2017-06-23 |
Family
ID=53458070
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310728104.XA Active CN104734531B (en) | 2013-12-24 | 2013-12-24 | Frequency converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104734531B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107378130A (en) * | 2017-08-24 | 2017-11-24 | 太仓贝斯特机械设备有限公司 | A kind of peeling machine automatically controlled |
| RU175937U1 (en) * | 2017-06-21 | 2017-12-25 | федеральное государственное бюджетное образовательное учреждение высшего образования "Алтайский государственный технический университет им. И.И. Ползунова" (АлтГТУ) | Transistor frequency converter with compact control system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2755859Y (en) * | 2004-12-31 | 2006-02-01 | 海尔集团公司 | Power factor compensator of frequency-variable air conditioner |
| US20070152624A1 (en) * | 2005-12-29 | 2007-07-05 | Samsung Electronics Co., Ltd. | Motor system, control method thereof, and compressor using the same |
| CN102255542A (en) * | 2011-07-20 | 2011-11-23 | 南京航空航天大学 | Single-stage boosting inverter with tap inductor |
| CN203674989U (en) * | 2013-12-24 | 2014-06-25 | 珠海格力电器股份有限公司 | Frequency converter |
-
2013
- 2013-12-24 CN CN201310728104.XA patent/CN104734531B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2755859Y (en) * | 2004-12-31 | 2006-02-01 | 海尔集团公司 | Power factor compensator of frequency-variable air conditioner |
| US20070152624A1 (en) * | 2005-12-29 | 2007-07-05 | Samsung Electronics Co., Ltd. | Motor system, control method thereof, and compressor using the same |
| CN102255542A (en) * | 2011-07-20 | 2011-11-23 | 南京航空航天大学 | Single-stage boosting inverter with tap inductor |
| CN203674989U (en) * | 2013-12-24 | 2014-06-25 | 珠海格力电器股份有限公司 | Frequency converter |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU175937U1 (en) * | 2017-06-21 | 2017-12-25 | федеральное государственное бюджетное образовательное учреждение высшего образования "Алтайский государственный технический университет им. И.И. Ползунова" (АлтГТУ) | Transistor frequency converter with compact control system |
| CN107378130A (en) * | 2017-08-24 | 2017-11-24 | 太仓贝斯特机械设备有限公司 | A kind of peeling machine automatically controlled |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104734531B (en) | 2017-06-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20180269795A1 (en) | Bidirectional resonant conversion circuit and converter | |
| CN205283423U (en) | Three -phase PFC rectifier circuit | |
| CN102281006A (en) | Novel three-level soft switching converter | |
| WO2012010053A1 (en) | Transformer-less static synchronous compensator (statcom) topological structure based on modular multilevel converter (mmc) | |
| CN101394091B (en) | Voltage feedback single-stage power factor calibrating circuit | |
| CN107888073B (en) | Alternating current-direct current hybrid energy router of all-round soft switch | |
| CN108736756B (en) | Improved double-auxiliary resonant-pole three-phase soft switching inverter circuit | |
| CN204190636U (en) | PWM rectifier circuit topological structure | |
| CN104253549A (en) | LCL filtering-based circuit topology structure of high-power PWM (pulse-width modulation) rectifier | |
| CN102263513B (en) | AC-DC isolated conversion circuit | |
| CN102983738A (en) | Primary voltage buffer type full-bridge single-stage power-factor corrector of transformer | |
| CN102255356A (en) | Efficient uninterruptible power supply | |
| CN104734531A (en) | Frequency converter | |
| CN105978322A (en) | Switch capacitor type high-gain quasi Z source DC-DC converter | |
| CN203674989U (en) | Frequency converter | |
| CN106253458B (en) | A kind of uninterruptible power supply and its control method | |
| CN204190641U (en) | Based on the high-power PWM rectifier circuit topological structure of LCL filtering | |
| CN110061523B (en) | Multifunctional single-phase grid-connected inversion system and method with novel topological structure | |
| WO2021120354A1 (en) | Three-phase ac-dc conversion power source | |
| CN104270019A (en) | PWM rectifier circuit topology structure | |
| CN107134938B (en) | Single-phase three-level half-bridge inverter capable of realizing capacitor voltage equalizing | |
| CN116614003B (en) | Isolated bidirectional DC/DC conversion circuit | |
| CN216599433U (en) | Bidirectional DC-DC circuit of grid-connected and off-grid dual-mode single-phase photovoltaic energy storage system | |
| CN204835962U (en) | Voltage doubler rectifier circuit | |
| CN204271658U (en) | A kind of phase three-wire three parallel connection type dynamic voltage compensator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |