CN109149922B - Power factor correction circuit and alternating current charger for electric automobile using same - Google Patents
Power factor correction circuit and alternating current charger for electric automobile using same Download PDFInfo
- Publication number
- CN109149922B CN109149922B CN201811042818.4A CN201811042818A CN109149922B CN 109149922 B CN109149922 B CN 109149922B CN 201811042818 A CN201811042818 A CN 201811042818A CN 109149922 B CN109149922 B CN 109149922B
- Authority
- CN
- China
- Prior art keywords
- circuit
- signal
- output
- factor correction
- boost circuits
- 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.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
- H02M1/4208—Arrangements for improving power factor of AC input
- H02M1/4225—Arrangements for improving power factor of AC input using a non-isolated boost converter
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
- H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
- H02M3/1584—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load with a plurality of power processing stages connected in parallel
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Abstract
The invention relates to a power factor correction circuit, which comprises two groups of Boost circuits which are connected in parallel and work alternately and a control circuit which outputs control signals corresponding to different working modes to control the Boost circuits: the working mode comprises a fixed frequency mode, a variable frequency mode and a frequency hopping mode; when a fixed frequency mode is adopted, the control signals received by the two groups of Boost circuits are fixed frequency PWM signals adopting the maximum frequency; when a frequency conversion mode is adopted, the control signals received by the two groups of Boost circuits are frequency conversion PWM signals according to whether the corresponding inductive current reaches a reference amplitude value; in the frequency hopping mode, the two groups of Boost circuits receive control signals which are a series of pulse signals only output when the output voltage of the AC/DC converter is reduced to a set voltage threshold value. The invention also relates to an alternating current charger for the electric automobile, which adopts the power factor correction circuit. According to the invention, the power factor correction stage of the alternating current charger keeps high efficiency in a full load range by adopting different control strategies in different load intervals.
Description
Technical Field
The invention relates to the technical field of power electronics, in particular to an alternating current charger of an electric automobile and a power factor correction circuit therein.
Background
As energy shortages become one of the global crises, today's major fossil fuel-powered vehicles are being gradually replaced by electric vehicles. However, due to the limitation of the energy density of the battery, the endurance mileage of the electric vehicle is always subjected to a problem. To solve this problem, an effective method is to establish a charging facility that is widely distributed and convenient to use.
Heretofore, charging facilities for electric vehicles are mainly classified into an ac charger and a dc charging pile. The alternating current charger is usually a vehicle-mounted AC/DC converter lower than 15kW, and is suitable for low-speed charging scenes such as commercial use and household use; and the independent direct current charging pile which is usually lower than 250kW is more suitable for scenes such as an expressway and the like which need quick charging.
For an alternating current charger of an electric vehicle, a general architecture is AC/DC with a power factor correction function plus DC/DC with electrical isolation and voltage reduction functions. As a power source of an electric vehicle, the charging characteristics of a lithium battery generally include three stages, namely, pre-charging, constant current, and constant voltage. To achieve energy efficient conversion at each stage, the power factor correction stage in the ac charger should maintain high efficiency over the full load range. Currently, the commonly used power factor correction topologies are: the interleaved parallel Boost converter has the characteristics of small input and output current ripples, simple EMI filter and high efficiency; the bridgeless Boost converter replaces two diodes in the rectifier bridge with the MOSFETs, so that the efficiency is improved, and the circuit structure is simplified; a semi-bridgeless Boost converter well solves the EMI interference problem existing in the bridgeless Boost converter.
The above-mentioned research works are almost all dedicated to improving the conversion efficiency by improving the hardware structure, and the effect is significant only at a certain load point or a certain load interval, but the full load range cannot be considered.
Disclosure of Invention
The invention aims to provide a power factor correction circuit capable of keeping high efficiency in a full load range and an alternating current charger for an electric automobile using the same.
In order to achieve the purpose, the invention adopts the technical scheme that:
a power factor correction circuit applied to an AC/DC converter of an AC charger for an electric vehicle, the AC/DC converter including an AC/DC conversion circuit, an input terminal of the power factor correction circuit being connected to the AC/DC conversion circuit, an output terminal of the power factor correction circuit forming an output terminal of the AC/DC converter and being connected to a load, characterized in that: the power factor correction circuit includes:
the two groups of Boost circuits are connected in parallel, the input ends of the Boost circuits are connected with the AC/DC conversion circuit, the output ends of the Boost circuits are connected with the load, each Boost circuit comprises an inductor, a main control tube and a freewheeling diode, and the main control tubes in the two groups of Boost circuits are switched on or off based on respective corresponding control signals to realize the alternate work of the two groups of Boost circuits;
the control circuit outputs control signals corresponding to different working modes to the main control tubes of the two groups of Boost circuits respectively according to the load power P of the AC/DC converter;
the working modes comprise a fixed frequency mode, a variable frequency mode and a frequency hopping mode;
when the load power P of the AC/DC converter is larger than or equal to a first load boundary value, the constant frequency mode is adopted, and the control signals received by the two groups of Boost circuits are constant frequency PWM signals which are output by the control circuit and adopt a set maximum frequency; when the first load boundary value is larger than the load power P of the AC/DC converter and is larger than or equal to the second load boundary value, the frequency conversion mode is adopted, and the control signals received by the two groups of Boost circuits are frequency conversion PWM (pulse width modulation) signals output by the control circuit according to whether the corresponding inductive current reaches a reference amplitude value or not; when the load power P of the AC/DC converter is less than a second load boundary value, the frequency hopping mode is adopted, and the control signals received by the two groups of Boost circuits are a series of pulse signals output by the control circuit only when the output voltage of the AC/DC converter is reduced to a set voltage threshold value; the full load power of the AC/DC converter is greater than the first load boundary value and greater than the second load boundary value.
Preferably, the control circuit includes:
the output voltage sampling module is used for collecting the output voltage of the AC/DC converter and outputting a voltage signal;
a multi-threshold comparison unit for outputting a corresponding mode selection signal according to a comparison result of the load power P of the AC/DC converter and a set threshold value therein;
the signal output module is used for outputting a corresponding control signal according to the current mode selection signal or the current signal/the voltage signal obtained by collecting the current mode selection signal and the inductive current;
the input end of the output voltage sampling module is connected with the output end of the Boost circuit, the input end of the multi-threshold comparison unit is connected with the output end of the sampling module, the input end of the signal output module is respectively connected with the multi-threshold comparison unit, the Boost circuit and the output voltage sampling module, and the output end of the signal output module is respectively connected with the main control tubes of the two groups of Boost circuits.
Preferably, the signal output module includes a PWM comparator for generating the fixed-frequency PWM signal or the variable-frequency PWM signal corresponding to a main control transistor in a group of the Boost circuits, a delay circuit, and a Ton generator for generating the series of pulse signals corresponding to a main control transistor in a group of the Boost circuits, an input end of the PWM comparator is connected to the Boost circuits and the voltage sampling module respectively and inputs a product signal of an input voltage and an output voltage of the Boost circuits, the current signal, and a main control transistor on-off signal obtained according to the current signal, the output voltage signal is connected to the PWM comparator through a first switch controlled by the mode selection signal, the main control transistor on-off signal is connected to the PWM comparator through a second switch controlled by the mode selection signal, and an output end of the PWM comparator is divided into two paths, one path is connected to one group of the Boost circuits, and the other path is connected to the other group of the Boost circuits after passing through a delay circuit; the input end of the Ton generator is connected with the multi-threshold comparison unit, and the output end of the Ton generator is connected to the output end of the PWM comparator.
Preferably, the signal output module further includes a current sampling circuit for collecting the inductive current and outputting the current signal, a zero-cross detection circuit for judging the open state of a main control tube in the Boost circuit and outputting an open signal of the main control tube, and a multiplier for realizing the multiplication of the input voltage and the output voltage of the Boost circuit and outputting the product signal, an input end of the current sampling circuit is connected with the Boost circuit, one output end of the current sampling circuit is connected with one input end of the PWM comparator, an input end of the zero-cross detection circuit is connected with the other output end of the current sampling circuit, an output end of the zero-cross detection circuit is connected with the other input end of the PWM comparator through the second switch, and one input end of the multiplier is connected with the input end of the Boost circuit, the output end of the output voltage sampling module is connected with the other input end of the multiplier through the first switch, and the output end of the multiplier is connected with the other input end of the PWM comparator.
Preferably, the current sampling circuit is connected with a group of the Boost circuits.
Preferably, the current sampling circuit is connected with the sources of the master control transistors in the group of Boost circuits.
Preferably, the main control tube is a silicon-based MOSFET, a silicon carbide MOSFET, a silicon-based gallium nitride MOSFET, a gallium nitride MOSFET or a gallium arsenide MOSFET.
Preferably, the freewheeling diode is a fast recovery diode, an ultrafast recovery diode or a silicon carbide diode.
Preferably, the frequency conversion mode is preset with a lowest frequency, and the frequency of the frequency conversion PWM signal is greater than or equal to the lowest frequency.
An alternating current charger for an electric automobile comprises an AC/DC converter with a power factor correction function, wherein the AC/DC converter comprises an AC/DC conversion circuit and a power factor correction circuit connected with the AC/DC converter, and the power factor correction circuit adopts the power factor correction circuit.
Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages: the invention adopts a multi-mode control strategy, and ensures that the power factor correction stage of the alternating current charger keeps high efficiency in a full load range by adopting different control strategies in different load intervals.
Drawings
Fig. 1 is a schematic circuit diagram of an AC/DC converter having a power factor correction function in an AC charger for an electric vehicle according to the present invention.
Detailed Description
The invention will be further described with reference to examples of embodiments shown in the drawings to which the invention is attached.
The first embodiment is as follows: an alternating current charger for an electric vehicle includes an AC/DC converter having a power factor correction function and a DC/DC converter having an electrical isolation and step-down function. As shown in fig. 1, the AC/DC converter further includes an AC/DC conversion circuit and a power factor correction circuit.
The AC/DC conversion circuit comprises a bridge conversion circuit formed by four diodes, wherein the input end of the bridge conversion circuit is the input end of the AC/DC converter and inputs an alternating current signal, the output end of the bridge conversion circuit is connected with the input end of the power factor correction circuit, and the output end of the power factor correction circuit forms the output end of the AC/DC converter and is connected with a load.
The power factor correction circuit comprises two groups of Boost circuits and a control circuit for controlling the two groups of Boost circuits to work, wherein the two groups of Boost circuits are connected in parallel to form a group of input ends and a group of output ends together, the input ends of the Boost circuits are connected with an AC/DC conversion circuit, the output ends of the Boost circuits are connected with a load, each group of Boost circuits comprises an inductor (the inductors in the two groups of Boost circuits are L1 and L2 respectively), a main control tube (the main control tubes in the two groups of Boost circuits are S1 and S2 respectively) and a freewheeling diode (the freewheeling diodes in the two groups of Boost circuits are D1 and D2 respectively), one end of the inductor forms an input end and is connected to the AC/DC conversion circuit, the other end of the inductor is divided into two paths, one path is connected with one end of the freewheeling diode, the other end of the freewheeling diode forms an output end, namely an output side positive polarity end, the other path is connected with the main control tube, the other end of the main control tube is connected with a grounding circuit reference, when the main control tubes are in different states of connection or disconnection, the two groups of the Boost circuits are connected in parallel, the two groups of the Boost circuits, the main control circuits are connected in parallel connection, the output voltage is consistent with the two groups of the master control circuits, the output voltage, the two groups of the master control circuits, the two.
Typically the master is a silicon-based MOSFET, a silicon carbide MOSFET, a silicon-based gallium nitride MOSFET, a gallium nitride MOSFET or a gallium arsenide MOSFET. The freewheeling diode is a fast recovery diode, an ultrafast recovery diode or a silicon carbide diode. With the rapid development of power switching device technology, new semiconductor materials are continuously being used. In order to improve the conversion efficiency of the circuit, increase the power density and reduce the electromagnetic emission, the MOSFET used in the scheme uses a silicon-based gallium nitride material. The silicon-based gallium nitride MOSFET greatly reduces the requirements on a driving circuit under the condition of keeping the advantages of high switching frequency, high temperature resistance, radiation resistance and the like of the traditional gallium nitride power device, and is easy to apply. The power diode adopts a silicon carbide diode, and the advantages of almost no reverse recovery greatly reduce the switching loss and the radiation interference.
The control circuit is used for outputting control signals corresponding to different working modes to the main control tubes of the two groups of Boost circuits respectively according to the load power P of the AC/DC converter, so that the work of the two groups of Boost circuits is controlled. The load state of the AC/DC converter is determined by using the percentage of the current output power to the full load output power, and several load boundary values, such as a first load boundary value and a second load boundary value, can be determined according to the percentage, wherein the full load power of the AC/DC converter is larger than the first load boundary value and larger than the second load boundary value. For the load power of the AC/DC converter, it is generally classified into a full load state (current load power of the AC/DC converter = full load power of the AC/DC converter), a heavy load state (full load power of the AC/DC converter > current load power of the AC/DC converter ≧ a first load boundary value), a medium/small power state (the first load boundary value > current load power of the AC/DC converter ≧ a second load boundary value), and a light load state (current load power of the AC/DC converter < the second load boundary value), and three operation modes are respectively adopted corresponding to the above different states of the current load power of the AC/DC converter. The load boundary values for determining the switching of the operation mode may be determined according to the voltage outer loop output value corresponding to the actual load boundary. A hysteresis loop of a slight width needs to be set at the boundary to prevent frequent switching.
The operation modes include a fixed frequency Mode (or called a Continuous Conduction Mode (CCM)), a variable frequency Mode (or called a Boundary Conduction Mode (BCM)), and a Multi-Cycle Mode (MCM). When the load power of the AC/DC converter is larger than or equal to a first load boundary value, namely in a heavy load or full load state, a fixed frequency mode is adopted, and control signals received by the two groups of Boost circuits are fixed frequency PWM signals which are output by the control circuit and adopt set maximum frequency. And when the first load boundary value is larger than the load power of the AC/DC converter and is not smaller than the second load boundary value, namely in a medium-load state, a frequency conversion mode is adopted, and the control signals received by the two groups of Boost circuits are frequency conversion PWM signals output by the control circuit according to whether the corresponding inductive current reaches the reference amplitude value or not. And when the load power of the AC/DC converter is less than the second load boundary value, namely in a light load state, a frequency hopping mode is adopted, and the control signals received by the two groups of Boost circuits are a series of pulse signals output by the control circuit only when the output voltage of the AC/DC converter is reduced to a set voltage threshold value.
In order to realize the output of the various control signals, the scheme of the control circuit is as follows: the control circuit comprises an output voltage sampling module, a multi-threshold comparison unit and a signal output module.
The output voltage sampling module is used for collecting the output voltage of the AC/DC converter and outputting a voltage signal, and the input end of the output voltage sampling module is connected with the output end of the Boost circuit. The output voltage sampling module comprises a voltage division circuit, a compensation circuit and an error amplifier, wherein the voltage division circuit is connected with the output end of the Boost circuit.
The input end of the multi-threshold comparison unit is connected with the output end of the output voltage sampling module and is used for outputting a corresponding mode selection signal according to the comparison result of the load power P of the AC/DC converter and the set threshold value. That is, a plurality of thresholds for comparing and determining which state the load power of the AC/DC converter belongs to are preset in the multi-threshold comparison unit, and then the current load state of the AC/DC converter is determined according to the output voltage of the AC/DC converter, that is, based on the collected output voltage of the Boost circuit, so as to output a mode selection signal corresponding to the working mode to be adopted.
The input end of the signal output module is respectively connected with the multi-threshold comparison unit, the Boost circuits and the output voltage sampling module, and the output end of the signal output module is respectively connected with the main control tubes of the two groups of Boost circuits. The signal output module is used for outputting corresponding control signals to the two groups of Boost circuits, and the signal output module outputs the control signals according to the current mode selection signals or outputs the corresponding control signals according to the current mode selection signals and current signals/voltage signals obtained by collecting inductive current. Specifically, the signal output module mainly includes a PWM comparator, a Ton generator, and a delay circuit, where the PWM comparator and the Ton generator are used to output control signals in different operating modes, respectively. The input end of the PWM comparator is respectively connected with the Boost circuit and the voltage sampling module, so that a product signal of input voltage and output voltage of the Boost circuit, a current signal and a master control tube on-off signal obtained according to the current signal are input. The output voltage signal is connected to the PWM comparator through a first switch controlled by the mode selection signal, and the main control tube opening signal is connected to the PWM comparator through a second switch controlled by the mode selection signal. The input of the Ton generator is connected to the multi-threshold comparison unit. The output end of the Ton generator is connected to the output end of the PWM comparator to form a common output end, the output end of the PWM comparator is divided into two paths, one path is connected into one group of Boost circuits, and the other path is connected into the other group of Boost circuits after passing through the delay circuit. The PWM comparator is used for generating a fixed-frequency PWM signal or a variable-frequency PWM signal corresponding to a main control tube in a group of Boost circuits, and the Ton generator is used for generating a series of pulse signals corresponding to the main control tube in the group of Boost circuits.
In order to meet the requirement of generating a fixed-frequency PWM signal or a variable-frequency PWM signal by a PWM comparator, the signal output module further comprises a current sampling circuit for acquiring inductive current and outputting a current signal, a zero-crossing detection circuit for judging the switching-on state of a main control tube in the Boost circuit and outputting a switching-on signal of the main control tube, and a multiplier for realizing multiplication calculation of input voltage and output voltage of the Boost circuit and outputting a product signal. The input end of the current sampling circuit is connected with a group of Boost circuits and can be connected with the source electrode of a main control tube in the group of Boost circuits, one output end of the current sampling circuit is connected with one input end of a PWM (pulse-width modulation) comparator, the input end of the zero-crossing detection circuit is connected with the other output end of the current sampling circuit, the output end of the zero-crossing detection circuit is connected with the other input end of the PWM comparator through a second switch, one input end of a multiplier is connected with the input end of the Boost circuits, the output end of an output voltage sampling module is connected with the other input end of the multiplier through a first switch, and the output end of the multiplier is connected with the other input end of the PWM comparator.
The acquisition of voltage, current, temperature information in the circuit and the boundary determination and switching of the three modes can be performed using a microcontroller with a high resolution, high precision, low latency ADC module and PWM module, such as the 16-bit digital signal controller chip dsPIC33EP series by Microchip Technology Inc or the TMS320F28 series by texas instruments Inc. Meanwhile, the chip is used for loop control and adjustment required by the stable work of the circuit and the response transient process.
The working principle of the power factor correction circuit is as follows: the direct current signal converted by the AC/DC conversion circuit is transmitted to a load in the power factor correction circuit through the Boost circuit working alternately. According to the size of the load, the control circuit outputs different control signals corresponding to different working modes to enable the two groups of Boost circuits to complete the functions of the Boost circuits, and according to the actual condition of the circuit load, the control modes are seamlessly switched among a fixed frequency mode, a variable frequency mode and a frequency hopping mode. When the load is full or heavy, the multi-threshold comparison unit controls the first switch to be closed, the PWM comparator outputs a fixed-frequency PWM signal based on the current state, one path of the fixed-frequency PWM signal is sent to one group of Boost circuits to control the main control tube S1 of the first switch, the other path of the fixed-frequency PWM signal is sent to the other group of Boost circuits to control the main control tube S2 of the first switch after passing through the delay circuit, so that the two groups of Boost circuits alternately work according to the preset highest frequency, the fixed-frequency mode is realized, and the smaller inductive current ripple and the smaller conduction loss are obtained. Efficiency can be improved by optimizing switching losses with silicon carbide diodes with little reverse recovery. When the circuit is in a medium load state, the multi-threshold comparison unit controls the first switch and the second switch to be closed, the zero-crossing detection circuit is used for judging the switching-on time of the main control tube, when the inductive current rises to the sine wave reference amplitude, the main control tube needs to be switched off, and based on the switching-on time, the PWM comparator outputs variable-frequency PWM signals, so that the two groups of Boost circuits change the working state based on the change of the inductive current. The frequency conversion mode can realize soft switching, greatly reduces the switching loss, has relatively small conduction loss due to small load, and optimizes the overall efficiency of the converter. In the frequency conversion mode, because the switching frequency of the circuit operation is reduced along with the reduction of the load, a lowest frequency can be preset correspondingly for the frequency conversion mode, so that the switching frequency of the main control tube controlled by the frequency conversion PWM signal is not reduced after being reduced to the lowest frequency, but is kept unchanged, namely the frequency of the frequency conversion PWM signal in the whole process is always greater than or equal to the lowest frequency. When the load is light, the control circuit outputs a series of pulse signals with fixed duty ratio through a Ton generator (a main control tube opening time generator) when the output voltage of the AC/DC converter is reduced to a set voltage threshold value, and then the main control tube is always in a turn-off state until the output voltage of the AC/DC converter is reduced to the set voltage threshold value again and outputs a series of pulse signals. The frequency hopping mode can greatly reduce the switching frequency and obviously improve the light load efficiency.
The power factor correction circuit has the advantages that: two groups of Boost circuits which are connected in parallel and work in a 180-degree staggered phase on a time sequence are adopted, so that voltage and current ripples of an input side and an output side are effectively reduced, the requirement on the capacitance value of a filter capacitor is lowered, and the design of an EMI filter of the input side is simplified; two groups of Boost circuits equally share output power, so that the heat dissipation of the converter is more uniform. In terms of control mode, the converter is operated in different operating modes depending on the actual load conditions. When the converter is in a heavy load or full load state, the converter is enabled to work in a constant frequency mode to obtain smaller inductive current ripple and conduction loss. At the same time, silicon carbide diodes with little reverse recovery are fitted to optimize switching losses and thus improve efficiency. When the load is in a medium and small power state, the zero-crossing detection circuit is used for judging the switching-on moment of the main pipe, and when the inductive current rises to the amplitude of the sine wave reference, the main pipe is switched off. The frequency conversion mode can realize soft switching, and greatly reduces switching loss. Meanwhile, as the load is not large, the conduction loss is relatively small, and the overall efficiency of the converter is optimized. When the converter is in a light load state, the control system continuously sends out a plurality of pulses with fixed duty ratio through a Ton generator (a main pipe opening time generator), and then the main pipe is always in an off state until the output voltage drops to a certain threshold value and then sends out a pulse sequence again. The frequency hopping mode greatly reduces the switching frequency and can obviously improve the light load efficiency. According to the scheme, through a specific circuit topology and a specific control method, the input voltage and the input current of the circuit are in the same phase as much as possible, and harmonic components contained in the input current waveform are reduced as much as possible.
The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.
Claims (10)
1. A power factor correction circuit applied to an AC/DC converter of an AC charger for an electric vehicle, the AC/DC converter including an AC/DC conversion circuit, an input terminal of the power factor correction circuit being connected to the AC/DC conversion circuit, an output terminal of the power factor correction circuit forming an output terminal of the AC/DC converter and being connected to a load, characterized in that: the power factor correction circuit includes:
the two groups of Boost circuits are connected in parallel, the input ends of the Boost circuits are connected with the AC/DC conversion circuit, the output ends of the Boost circuits are connected with the load, each Boost circuit comprises an inductor, a main control tube and a freewheeling diode, and the main control tubes in the two groups of Boost circuits are switched on or off based on respective corresponding control signals to realize the alternate work of the two groups of Boost circuits;
the control circuit outputs control signals corresponding to different working modes to the main control tubes of the two groups of Boost circuits respectively according to the load power P of the AC/DC converter;
the working modes comprise a fixed frequency mode, a variable frequency mode and a frequency hopping mode;
when the load power P of the AC/DC converter is larger than or equal to a first load boundary value, the constant frequency mode is adopted, and the control signals received by the two groups of Boost circuits are constant frequency PWM signals which are output by the control circuit and adopt a set maximum frequency; when the first load boundary value is larger than the load power P of the AC/DC converter and is larger than or equal to the second load boundary value, the frequency conversion mode is adopted, and the control signals received by the two groups of Boost circuits are frequency conversion PWM (pulse width modulation) signals output by the control circuit according to whether the corresponding inductive current reaches a reference amplitude value or not; when the load power P of the AC/DC converter is less than a second load boundary value, the frequency hopping mode is adopted, and the control signals received by the two groups of Boost circuits are a series of pulse signals output by the control circuit only when the output voltage of the AC/DC converter is reduced to a set voltage threshold value; the full load power of the AC/DC converter is greater than the first load boundary value and greater than the second load boundary value.
2. A power factor correction circuit according to claim 1, wherein: the control circuit includes:
the output voltage sampling module is used for collecting the output voltage of the AC/DC converter and outputting a voltage signal;
a multi-threshold comparison unit for outputting a corresponding mode selection signal according to a comparison result of the load power P of the AC/DC converter and a set threshold value therein;
the signal output module is used for outputting a corresponding control signal according to the current mode selection signal or the current signal/the voltage signal obtained by collecting the current mode selection signal and the inductive current;
the input end of the sampling module is connected with the output end of the Boost circuit, the input end of the multi-threshold comparison unit is connected with the output end of the output voltage sampling module, the input end of the signal output module is respectively connected with the multi-threshold comparison unit, the Boost circuit and the output voltage sampling module, and the output end of the signal output module is respectively connected with the main control tubes of the two groups of Boost circuits.
3. A power factor correction circuit according to claim 2, wherein: the signal output module comprises a PWM comparator used for generating the fixed-frequency PWM signal or the variable-frequency PWM signal corresponding to a main control tube in a group of the Boost circuits, a delay circuit and a Ton generator used for generating the series of pulse signals corresponding to the main control tube in the group of the Boost circuits, the input end of the PWM comparator is respectively connected with the Boost circuits and the voltage sampling module and is used for inputting a product signal of input voltage and output voltage of the Boost circuits, the current signal and a main control tube on-off signal obtained according to the current signal, the output voltage signal is accessed to the PWM comparator through a first switch controlled by the mode selection signal, the main control tube on-off signal is accessed to the PWM comparator through a second switch controlled by the mode selection signal, the output end of the PWM comparator is divided into two paths, and one path is accessed to one group of the Boost circuits, the other path of the signal is connected to the other group of Boost circuits after passing through the delay circuit; the input end of the Ton generator is connected with the multi-threshold comparison unit, and the output end of the Ton generator is connected to the output end of the PWM comparator.
4. A power factor correction circuit according to claim 3, wherein: the signal output module further comprises a current sampling circuit for collecting the inductive current and outputting the current signal, a zero-cross detection circuit for judging the open state of a main control tube in the Boost circuit and outputting the open signal of the main control tube, and a multiplier for realizing the multiplication calculation of the input voltage and the output voltage of the Boost circuit and outputting the product signal, wherein the input end of the current sampling circuit is connected with the Boost circuit, one output end of the current sampling circuit is connected with one input end of the PWM comparator, the input end of the zero-cross detection circuit is connected with the other output end of the current sampling circuit, the output end of the zero-cross detection circuit is connected with the other input end of the PWM comparator through the second switch, and one input end of the multiplier is connected with the input end of the Boost circuit, the output end of the output voltage sampling module is connected with the other input end of the multiplier through the first switch, and the output end of the multiplier is connected with the other input end of the PWM comparator.
5. The power factor correction circuit of claim 4, wherein: the current sampling circuit is connected with a group of Boost circuits.
6. The power factor correction circuit of claim 5, wherein: the current sampling circuit is connected with the source electrodes of the master control tubes in the group of Boost circuits.
7. A power factor correction circuit according to claim 1, wherein: the main control tube is a silicon-based MOSFET, a silicon carbide MOSFET, a gallium nitride MOSFET or a gallium arsenide MOSFET.
8. A power factor correction circuit according to claim 1, wherein: the freewheeling diode is a fast recovery diode, an ultrafast recovery diode or a silicon carbide diode.
9. A power factor correction circuit according to claim 1, wherein: the frequency conversion mode is preset with a lowest frequency correspondingly, and the frequency of the frequency conversion PWM signal is greater than or equal to the lowest frequency.
10. An AC charger for an electric vehicle, comprising an AC/DC converter having a power factor correction function, the AC/DC converter including an AC/DC conversion circuit and a power factor correction circuit connected to the AC/DC converter, characterized in that: the power factor correction circuit adopts a power factor correction circuit as claimed in any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811042818.4A CN109149922B (en) | 2018-09-07 | 2018-09-07 | Power factor correction circuit and alternating current charger for electric automobile using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811042818.4A CN109149922B (en) | 2018-09-07 | 2018-09-07 | Power factor correction circuit and alternating current charger for electric automobile using same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109149922A CN109149922A (en) | 2019-01-04 |
| CN109149922B true CN109149922B (en) | 2020-07-24 |
Family
ID=64827633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811042818.4A Active CN109149922B (en) | 2018-09-07 | 2018-09-07 | Power factor correction circuit and alternating current charger for electric automobile using same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109149922B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110880863B (en) * | 2019-11-29 | 2023-05-26 | 广东美的制冷设备有限公司 | Control method, control device, home appliance and computer readable storage medium |
| CN111697814B (en) * | 2020-05-21 | 2021-06-18 | 青岛理工大学 | Harmonic suppression method and device based on PFC circuit and frequency conversion equipment |
| CN112701902B (en) * | 2020-12-03 | 2022-06-21 | 北京动力源科技股份有限公司 | Control method and device of staggered parallel BCM Boost PFC converter |
| CN116404880B (en) * | 2023-04-04 | 2023-12-26 | 北京龙腾云海科技股份有限公司 | Efficient power supply system based on multi-path switch power supply parallel connection |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102118107A (en) * | 2009-12-31 | 2011-07-06 | Nxp股份有限公司 | Controller for power converting circuit |
| CN102318173A (en) * | 2007-06-22 | 2012-01-11 | 三多尼克爱特克两合股份有限公司 | Power factor corrector circuit for an electronic fluorescent lamp ballast |
| CN103378718A (en) * | 2012-04-20 | 2013-10-30 | 中国科学院电子学研究所 | Multi-mode step-down DC-DC converter in-chip soft start circuit |
| CN203278655U (en) * | 2012-12-24 | 2013-11-06 | 成都芯源系统有限公司 | control circuit and switching power supply |
| US8937469B2 (en) * | 2012-10-09 | 2015-01-20 | Delta-Q Technologies Corp. | Digital controller based detection methods for adaptive mixed conduction mode power factor correction circuit |
| CN105743343A (en) * | 2016-03-24 | 2016-07-06 | 西安电子科技大学昆山创新研究院 | High-efficiency DC-DC boost converter |
| CN106208697A (en) * | 2016-08-08 | 2016-12-07 | 成都芯源系统有限公司 | Step-up and step-down switching power converter and control circuit and control method thereof |
-
2018
- 2018-09-07 CN CN201811042818.4A patent/CN109149922B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102318173A (en) * | 2007-06-22 | 2012-01-11 | 三多尼克爱特克两合股份有限公司 | Power factor corrector circuit for an electronic fluorescent lamp ballast |
| CN102118107A (en) * | 2009-12-31 | 2011-07-06 | Nxp股份有限公司 | Controller for power converting circuit |
| CN103378718A (en) * | 2012-04-20 | 2013-10-30 | 中国科学院电子学研究所 | Multi-mode step-down DC-DC converter in-chip soft start circuit |
| US8937469B2 (en) * | 2012-10-09 | 2015-01-20 | Delta-Q Technologies Corp. | Digital controller based detection methods for adaptive mixed conduction mode power factor correction circuit |
| CN203278655U (en) * | 2012-12-24 | 2013-11-06 | 成都芯源系统有限公司 | control circuit and switching power supply |
| CN105743343A (en) * | 2016-03-24 | 2016-07-06 | 西安电子科技大学昆山创新研究院 | High-efficiency DC-DC boost converter |
| CN106208697A (en) * | 2016-08-08 | 2016-12-07 | 成都芯源系统有限公司 | Step-up and step-down switching power converter and control circuit and control method thereof |
Non-Patent Citations (2)
| Title |
|---|
| Light Load Efficiency Improvement for AC/DC Boost PFC Converters by Digital Multi-Mode Control Method;Wei-Shung Wang et al.;《IEEE PEDS 2011》;20111208;第1025-1030页 * |
| 功率因数校正技术的控制策略综述;李玉玲等;《通信电源技术》;20031231(第6期);第24-28页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109149922A (en) | 2019-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109149922B (en) | Power factor correction circuit and alternating current charger for electric automobile using same | |
| Tang et al. | A bridgeless totem-pole interleaved PFC converter for plug-in electric vehicles | |
| Park et al. | Soft-switched CCM boost converter with high voltage gain for high power applications | |
| Christen et al. | Highly efficient and compact DC-DC converter for ultra-fast charging of electric vehicles | |
| CN107968471B (en) | LCLC resonance circuit, wide-range constant-power output direct-current charger and control method | |
| CN108539980B (en) | Bidirectional DC/DC converter | |
| CN110828918A (en) | Control system and control method for automobile power battery | |
| CN115189578A (en) | Isolated bidirectional charger CLLC converter control device and method | |
| CN110572069A (en) | Bidirectional DC-AC converter | |
| CN113346750A (en) | Soft switching in-phase buck-boost converter based on coupling inductor and control method | |
| CN110445227B (en) | Method for inhibiting high-frequency and low-frequency ripple current in vehicle-mounted single-phase charging system of electric automobile | |
| US20140361742A1 (en) | Electric vehicle charger | |
| Bandeira et al. | A t-type isolated zero voltage switching DC–DC converter with capacitive output | |
| WO2023246512A1 (en) | Multi-level direct current converter, voltage control method for flying capacitor, and control apparatus | |
| Dung et al. | A DSP based digital control strategy for ZVS bidirectional Buck+ Boost converter | |
| Kim et al. | Design and control methods of bidirectional DC-DC converter for the optimal DC-link voltage of PMSM drive | |
| Zhan et al. | A high step-up bidirectional isolated dual-active-bridge converter with three-level voltage-doubler rectifier for energy storage applications | |
| Wu et al. | Analysis and design for a new ZVS dc–dc converter with active clamping | |
| CN114583959B (en) | Soft switch MPPT controller and photovoltaic power system | |
| Yan et al. | Securing full-load-range zero voltage switching for a dual active bridge based electric vehicle charger | |
| CN103269160A (en) | Three-state direct current-direct current converter and control method thereof | |
| Jayaprakash et al. | A new single-stage solar based controlled full-bridge DC-DC converter | |
| CN110087366B (en) | LED lighting Cuk-LLC three-port circuit and fuzzy prediction method thereof | |
| Matsui et al. | Analysis and improvement of bilateral chopper having current resonant soft-switch | |
| CN202840955U (en) | Electric power electronic converter and direct current boost circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |