CN117353364A - Correction power factor control system without input sensor - Google Patents

Correction power factor control system without input sensor Download PDF

Info

Publication number
CN117353364A
CN117353364A CN202310369637.7A CN202310369637A CN117353364A CN 117353364 A CN117353364 A CN 117353364A CN 202310369637 A CN202310369637 A CN 202310369637A CN 117353364 A CN117353364 A CN 117353364A
Authority
CN
China
Prior art keywords
signal
current
input
voltage
regulating
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.)
Pending
Application number
CN202310369637.7A
Other languages
Chinese (zh)
Inventor
丁习兵
董吉恒
高月
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Sword Electric Industrial Co ltd
Original Assignee
Beijing Sword Electric Industrial Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Beijing Sword Electric Industrial Co ltd filed Critical Beijing Sword Electric Industrial Co ltd
Priority to CN202310369637.7A priority Critical patent/CN117353364A/en
Publication of CN117353364A publication Critical patent/CN117353364A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/01—Arrangements for reducing harmonics or ripples
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/50—Controlling the sharing of the out-of-phase component

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Rectifiers (AREA)

Abstract

The invention relates to the field of drive control, and provides a correction power factor control system without an input sensor, which aims to solve the problem of harmonic interference of a chopper circuit of a power device. The system comprises: the device comprises a voltage regulating unit, a current regulating unit and a signal modulating unit, wherein the voltage regulating unit is used for regulating a voltage signal, and performing proportional and integral regulation after difference is carried out on an input voltage signal to generate a voltage regulating signal, and the input voltage signal comprises an input given voltage signal and a load feedback voltage signal; the current adjusting unit is used for adjusting current signals, adjusting input voltage adjusting signals and the input current signals and generating adjusting current signals; the signal modulation unit is used for modulating the circuit adjusting signal and generating a PWM signal for controlling the on-off of the switching device. The system has the advantages of simple structure, low cost, restraining the harmonic influence of input current, improving the power factor of a power supply and improving the adaptability of the system to a power grid.

Description

Correction power factor control system without input sensor
Technical Field
The invention relates to the field of drive control, in particular to a correction power factor control system without an input sensor.
Background
The power electronic device is mostly connected with a power grid through a semiconductor power device, the semiconductor power device is a nonlinear circuit, and a large amount of current harmonic waves and reactive power generated in the power grid pollute the power grid to become power pollution. The method for restraining the harmonic wave generated by the power electronic device mainly comprises the following steps: by-pass or eliminate harmonics by using an marginless filter or an edge filter circuit; harmonics are reduced and the power factor is increased by a Power Factor Correction (PFC) circuit.
The traditional PFC control adopts a voltage control and current control double-loop control mode, and in the voltage control, a phase-locked loop needs to be added for correcting current harmonic waves and power factors of input current, namely, sampling input voltage to carry out phase locking. After the phase-locked loop is introduced, an additional input voltage detection sensor needs to be added, so that the cost is high, and the circuit is complex; when voltage harmonic wave occurs at the common point of the power grid voltage, the voltage harmonic wave enters a current control loop through a phase-locked loop, the current harmonic wave is increased, positive feedback divergence is formed, power grid pollution is caused, and system faults occur.
The input-sensor-free correction power factor control system reduces the harmonic content of current in a power supply, improves the power factor and meets the requirements of a power grid.
Disclosure of Invention
In order to solve the above problems in the prior art, that is, in order to solve the problem in the power factor correction system, the phase-locked loop needs an additional input voltage detection sensor, which has high cost and complex circuit; when voltage harmonics appear at the common point of the power grid voltage, the power grid voltage harmonics enter a current control loop through a phase-locked loop, the current harmonics are increased, positive feedback divergence is formed, and the problem of power grid pollution is caused. The invention adopts the following technical scheme to solve the problems:
the application provides an input-less sensor correction power factor control system, comprising: the device comprises a voltage regulating unit, a current regulating unit and a signal modulating unit, wherein the voltage regulating unit is used for regulating a voltage signal, and performing proportional and integral regulation after difference is carried out on an input voltage signal to generate a voltage regulating signal, and the input voltage signal comprises an input given voltage signal and a load feedback voltage signal; the current adjusting unit is used for adjusting a current signal, adjusting an input voltage adjusting signal and the input current signal, and generating an adjusting current signal; the signal modulation unit is used for modulating the current regulation signal and generating a PWM signal for controlling the on-off of the switching device.
In some examples, the current regulation unit includes a multiplication module that multiplies the input voltage regulation signal and the load feedback voltage signal to generate a multiplication signal.
In some examples, the current adjustment unit includes a division module that performs a division operation on the multiplication signal and the input current to generate a division signal.
In some examples, the current adjustment unit includes a subtraction module that performs a subtraction operation on a predetermined step signal and the division signal to generate the current adjustment signal.
In some examples, the modulation unit performs superposition modulation on the current adjustment signal and a preset modulation signal, and generates a PWM signal for controlling on-off of the switching device.
According to the input-sensor-free correction power factor control system, the current adjusting unit is used for constructing the turn-off duty ratio enabling the input resistor to be of a resistive characteristic, so that harmonic influence of input current is restrained, the power factor of a power supply is improved, and the adaptability of the system to a power grid is improved. Meanwhile, a voltage sensor is not needed in the system, a phase-locked loop is not needed to be introduced, the cost is reduced, and the calculated amount of the MCU is reduced. The main circuit applicable to the power factor correction system has simple structure and low cost.
Drawings
Fig. 1 is a schematic diagram of an existing PFC control system according to an embodiment of the present application;
fig. 2 is a schematic diagram of a power factor correction PFC control system architecture constructed according to an embodiment of the present application.
Detailed Description
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are merely for explaining the technical principles of the present invention, and are not intended to limit the scope of the present invention.
It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other. The present application will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.
Fig. 1 shows a schematic diagram of a conventional PFC control system architecture. As shown in fig. 1, currently, the existing PFC control system is a dual loop control system, including voltage loop control and current loop control. In the current loop control, the input parameters include the magnitude of the input current and the phase of the input current, the input voltage is acquired by a sensor, and the phase of the input current is determined after the phase locking is performed through a phase-locked loop. When voltage harmonics occur in a power grid, the phase-locked loop is introduced into the current control loop, and current harmonics are introduced into the input of the current loop, so that positive feedback divergence is formed, and serious pollution is caused to the power grid. To meet the basic requirement of the power grid on input current harmonic waves, the embodiment of the application is based on the scheme that input impedance is controlled to be resistive through signal conversion, and the harmonic wave influence of the input current is reduced from an input end so as to correct input power factors.
With continued reference to fig. 2, fig. 2 is a schematic diagram of a PFC control system architecture according to an embodiment of the present application. As shown in fig. 2, in the present embodiment, the no-input sensor correction power factor control system includes a voltage adjusting unit, a current adjusting unit, and a signal modulating unit.
The voltage regulating unit and the current regulating unit collect information such as input current of a power supply, feedback voltage of a load and the like through a sensing device. The power supply is an ac power network for supplying power to the power device, and may be a three-phase ac power supply or a single-phase ac power supply. The input current is a current passing through the power supply when the power supply is operated to supply power to the power device. The feedback voltage refers to an output voltage of the power device or a voltage applied across a load by the power device.
The signal modulation unit is connected with the controllable switch devices in the power devices and outputs control signals to the controllable switch devices so as to control the on-off of each controllable switch device, thereby adjusting the output power of the power devices and the power factor of the input current and reducing the harmonic interference of the input current value.
The voltage regulating unit is used for regulating voltage signals, and the input signals have given reference voltage V ref And the load feedback voltage Vout, the voltage regulating unit is used for regulating the given reference voltage V ref And the load feedback voltage Vout, a bias voltage is generated, PI adjustment (proportional integral adjustment) is performed on the bias voltage, and a voltage adjustment signal Ve for adjusting the magnitude of the output voltage is generated. It can be understood that the load feedback voltage Vout is a voltage signal indicating the magnitude of the output voltage of the power device to the load, and reflects the magnitude of the output voltage of the power device according to a certain preset rule.
The regulation of the voltage regulating unit described above may be represented by the following logical process:
Ve＝Kp*(Vout-V ref )+ki*∫(Vout-V ref )dt (1)
in the above formula 1, ve is a voltage regulation signal, and is also an output signal of the voltage regulation unit; vout is load feedback voltage, V ref Given a reference voltage, kp is the scaling factor in the proportional-integral regulator and Ki is the integral factor in the proportional-integral regulator. The voltage regulating unit is used for setting a reference voltage V ref Performing follow-up control to enable the voltage output by the power device to be according to a given reference voltage V ref The indicated voltage level is running.
It is understood that the adjustment of the input offset voltage by the voltage adjustment unit described above is not limited to PI adjustment. The purpose of the voltage regulating unit is to give a reference voltage V ref Under the action of (a) the power device is based on a given reference voltage V ref And outputting according to the set logic.
The current adjusting unit is used for adjusting the current signal, and is used for adjusting the input voltage adjusting signal and the input current signal to generate an adjusting current signal. In this embodiment, the purpose of the current adjusting unit is to adjust the current in the main loop passing through the power supply, the power device and the load, so that the harmonic interference of the current in the main loop is reduced, and the impedance in the main loop is controlled to have a resistive characteristic by the adjustment of the current adjusting unit. When the main loop impedance is resistive, the input power factor is 1, and the harmonic interference is minimized.
The signal modulation unit is used for modulating the current regulation signal input from the current regulation unit and generating a PWM signal for controlling the on-off of the switching device. The on-off of the switching device is controlled by controlling the PWM signal applied to the control end of the switching device, so that the power supply can supply power to the load.
In this embodiment, the current adjusting unit includes a multiplying module that multiplies the input voltage adjusting signal and the load feedback voltage signal to generate a multiplied signal. The multiplication module performs multiplication operation, and the input signals of the multiplication module are the voltage regulating signal Ve and the load feedback voltage signal Vout. The voltage regulating signal Ve is an output signal of the voltage regulating unit, and the load feedback voltage signal Vout is a feedback signal of a voltage output by the power device. The multiplication module is represented by the following logic:
K＝Ve*Vout (2)
where Ve is the voltage regulation signal, vout is the load feedback voltage signal, K is the multiplication signal, i.e. the output of the multiplication module.
Further, the current adjusting unit includes a division module, and the division module performs a division operation on the multiplication signal and the input current to generate a division signal. In this embodiment, the division module performs a division operation on a signal input from the input terminal. The signals input by the input end of the division module are a multiplication signal K and an input current I in Wherein the current I is input in Representing the current input to the power device, the sampling point is after the filter inductance between the power supply and the power device, the current is the same as the current through the inductance, I l Representing the inductor current. The division module is represented by the following logic:
wherein I is l Is inductor current, I in Is input current, K is multiplication signal, D off The division signal is also the output of the division module.
Further, the current adjusting unit includes a subtracting module, and the subtracting module performs a subtracting operation on a predetermined step signal and the division signal to generate a subtracted signal. In this embodiment, the subtracting module performs a subtracting operation on the signal input from the input terminal. The signals input by the input end of the subtraction module are as follows: division signal D off And a predetermined step signal 1. The step signal 1 is a predetermined high level signal. The above subtracting module is represented by the logic:
D on ＝1-D off (4)
wherein D is on Is a subtraction signal, 1 is a step signal, D off For dividing the signal, subtracting the signal D on Is the output of the subtraction module and is also the output of the current regulating unit.
In this embodiment, the current adjusting unit is a series combination of the multiplying module, the dividing module and the subtracting module, and the input signal of the current adjusting unit is: load feedback voltage signal Vout, voltage regulation signal Ve, inductor current I l And step signals 1, wherein each input signal is input to different positions of the current regulating unit, and the output signals of the current regulating unit are as follows: subtraction signal D on . In the current adjusting unit, the subtraction signal D on The signal is output by the subtracting module and is also output by the current regulating module; subtraction signal D output by current regulation module on Is a scaling factor of a modulated signal, is a scaling factor of a high level of the modulated signal. Further, subtracting signal D on For modulating the duty cycle of the signal. Division signal D 0ff Is an intermediate signal of the current adjusting unit, is also a proportionality coefficient of a modulation signal, and is a proportionality coefficient of a low level of the modulation signal.
Further, the above signal modulationMeans for subtracting the signal D outputted from the current adjusting means on And performing superposition modulation with a preset modulation signal to generate a PWM signal for controlling the on-off of the switching device.
In the present embodiment, the subtraction signal D is outputted from the current adjusting unit on Superimposed modulation with a predetermined modulation signal, i.e. the duty ratio D of the output of the current regulating unit on And carrying out superposition modulation with a preset modulation signal to generate a PWM signal, wherein the PWM signal is used for controlling the on-off of the control switch device so as to control the power device.
In the embodiment of the application, the current regulating unit is used for meeting the basic requirement of the power grid on input current harmonic waves, and the input impedance is constructed to be resistive through signal conversion. The design process of the current regulator based on the requirements is as follows:
first, the relationship between input and output based on power device boost conversion can be:
Vin＝Vout*Toff/Tsw (5)
wherein Vin is an input voltage, i.e. the voltage input from the power supply to the power device; vout is the output voltage, i.e. the voltage output by the power device; toff is the off time and Tsw is the switching period.
Second, the relationship of the input impedance is determined by the input voltage and current:
in the above formula, zin is input impedance, I in To input current, I l For inductor current and input current I in The same applies.
The following impedance relationship can be obtained from equations 5 and 6:
in the above equation, doff is the duty cycle of turning off the power device.
In order to control Zin to be a resistive property, I must be eliminated l I.e. the control loop can be constructed such that the control quantity doff=m×i l M is a coefficient.
The input impedance can thus be reduced to:
the Zin can be controlled to have a resistive characteristic by controlling the coefficient M.
In view of stable control of voltage, M is constructed as follows:
combining equation 2 and to eliminate inductor current I l Doff=m×i of the inductive component structure in (a) l For the purpose of (a) a division module may be usedTo cancel the load feedback voltage Vout term in the input impedance zin=vout×m.
Ve is the voltage control loop output and Zin further evolves to:
by constructing the coefficient M, the purpose of power factor correction is realized, and meanwhile, the input voltage Vin does not need to be sampled, and a phase-locked loop circuit is not needed to confirm the phase of the input voltage Vin. It should be noted that the coefficient M may have different transformation forms, for example, M may also be constructed by the following form:
M＝Ve*Vout (11)
in this case, to eliminate the inductor current I l Is capable of eliminating interference of load feedback voltage by constructingAchieving the purpose.
Whatever the implementation, the objective is to adjust the input impedance to the resistive characteristic by signal conversion by the current adjustment unit, thereby achieving power factor correction.
With continued reference to fig. 2, in the current regulation unit, the multiplication module builds a factor K for the voltage regulation signal Ve and the load feedback voltage signal Vout through the input, and the division module builds from the input inductor current and the factor KThe division module can be obtained to construct +.>Wherein Ve is the output of the voltage regulating unit, < >>The input impedance is related to the input impedance, and the term is counteracted with the input impedance term after the voltage is fed into the voltage regulating main loop of the power device, so that when voltage harmonics appear at the common point of the power grid voltage, the voltage loop does not cause current harmonics after the voltage is fed into the current control loop, and the voltage loop can be used as disturbance, and new balance can be fed through disturbance adjustment.
Under the control of the correction power factor control system based on the no-input sensor, the current and the voltage of the input end of the power supply are monitored, the input voltage and the input current are sinusoidal, the power factor is close to 1, and the harmonic content is small.
Compared with the prior art, the application has the following beneficial effects:
the main circuit where the system is located has simple structure and low cost;
the voltage sensor is not needed, so that the system cost is reduced; and a phase-locked loop is not required to be introduced, so that the cost is reduced, the calculated amount of the MCU is reduced, meanwhile, the current harmonic wave is restrained, and the adaptability to a power grid is improved.
Thus far, the technical solution of the present invention has been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present invention is not limited to these specific embodiments. Equivalent modifications and substitutions for related technical features may be made by those skilled in the art without departing from the principles of the present invention, and such modifications and substitutions will fall within the scope of the present invention.

Claims (5)

1. An input-less sensor-corrected power factor control system, the system comprising: a voltage regulating unit, a current regulating unit and a signal modulating unit, wherein,
the voltage regulating unit is used for regulating voltage signals, performing proportional and integral regulation after the input voltage signals are subjected to difference, and generating voltage regulating signals, wherein the input voltage signals comprise input given voltage signals and load feedback voltage signals;
the current regulating unit is used for regulating a current signal, regulating the input voltage regulating signal, the load feedback voltage signal and the input current signal, and generating a regulating current signal;
the signal modulation unit is used for modulating a signal for controlling the on-off of a switch of the power device, and the signal modulation unit is used for modulating according to the current regulation signal and a preset modulation signal to generate a PWM signal for controlling the on-off of the switch device.
2. The sensorless corrected power factor control system of claim 1 wherein the current adjustment unit includes a multiplication module that multiplies the input voltage adjustment signal and the load feedback voltage signal to generate a multiplication signal.
3. The sensorless correction power factor control system of claim 2 wherein the current adjustment unit includes a division module that divides the multiplication signal and the input current to generate a division signal.
4. The sensorless correction power factor control system of claim 3 wherein the current adjustment unit includes a subtraction module that subtracts the predetermined step signal and the division signal to generate an adjusted current signal.
5. The system according to claim 4, wherein the modulating unit performs superposition modulation on the current adjusting signal and a preset modulating signal to generate a PWM signal for controlling on/off of the switching device.
CN202310369637.7A 2023-04-07 2023-04-07 Correction power factor control system without input sensor Pending CN117353364A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310369637.7A CN117353364A (en) 2023-04-07 2023-04-07 Correction power factor control system without input sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310369637.7A CN117353364A (en) 2023-04-07 2023-04-07 Correction power factor control system without input sensor

Publications (1)

Publication Number Publication Date
CN117353364A true CN117353364A (en) 2024-01-05

Family

ID=89363843

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310369637.7A Pending CN117353364A (en) 2023-04-07 2023-04-07 Correction power factor control system without input sensor

Country Status (1)

Country Link
CN (1) CN117353364A (en)

Similar Documents

Publication Publication Date Title
US5631550A (en) Digital control for active power factor correction
EP2919374B1 (en) Duty-ratio controller
US9812951B2 (en) Advanced PFC voltage controller
US7660135B2 (en) Universal AC high power inveter with galvanic isolation for linear and non-linear loads
US9577429B2 (en) Paralleling of active filters with independent controls
WO1994010744A1 (en) Active power line conditioner with synchronous transformation control
WO1997012437A1 (en) Controller for pwm-controlled converter
US11637493B2 (en) Electrical circuits for power factor correction by measurement and removal of overtones and power factor maximization
CN102025266B (en) Numeric control method for liquid level control (LLC) resonant conversion circuit
KR101562848B1 (en) Method for uninterruptible power supply system control by using active damping control scheme and repeat control techniques
US20140191743A1 (en) Current mode control arrangement and method thereof
US7015682B2 (en) Control of a power factor corrected switching power supply
Zhang et al. MIMO control of a high-step-up isolated bidirectional DC–DC converter
US11552554B2 (en) Electrical circuits for power factor correction by measurement and removal of overtones using a constant or slowly varying first frequency
US20220263428A1 (en) Power converting apparatus and photovoltaic module including the same
KR101870749B1 (en) Control apparatus for grid connected type single stage forward-flyback inverter
JP4872090B2 (en) Voltage regulator
CN117353364A (en) Correction power factor control system without input sensor
JP2012231606A (en) System interconnection power conversion device
AU2008357911B2 (en) Control method for a structure converting direct current into alternating current
CN114448251A (en) Digital control harmonic compensation circuit
Pahlevaninezhad et al. An optimal Lyapunov-based control strategy for power factor correction AC/DC converters applicable to electric vehicles
US20230208284A1 (en) Systems and Methods of Unwanted Harmonic Content Removal for Power Conversion
Ganacim et al. Output power feedforward technique applied to a high power factor rectifier with high frequency transformer
CN114362506B (en) Power factor correction circuit

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication