CN113890324A - Alternating current switching power supply for realizing mixed conduction mode based on long dead time - Google Patents

Alternating current switching power supply for realizing mixed conduction mode based on long dead time Download PDF

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CN113890324A
CN113890324A CN202111139463.2A CN202111139463A CN113890324A CN 113890324 A CN113890324 A CN 113890324A CN 202111139463 A CN202111139463 A CN 202111139463A CN 113890324 A CN113890324 A CN 113890324A
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dead time
current
module
switching
long dead
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CN113890324B (en
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张宇
鲁博
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Huazhong University of Science and Technology
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Huazhong University of Science and Technology
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    • 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
    • H02M1/38—Means for preventing simultaneous conduction of switches
    • 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
    • H02M1/12—Arrangements for reducing harmonics from ac input or output
    • H02M1/126—Arrangements for reducing harmonics from ac input or output using passive filters
    • 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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal 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
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal 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, e.g. single switched pulse inverters
    • H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal 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, e.g. single switched pulse inverters in a bridge configuration
    • H02M7/53871—Conversion of dc power input into ac power output without possibility of reversal 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, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
    • 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

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

The invention discloses an alternating current switching power supply for realizing a mixed conduction mode based on long dead time, which belongs to the field of switching power supplies and comprises the following components: an inversion module; the outer ring control module is used for carrying out PID control on the LC filtered signals in the inverter module and then outputting the signals; the inner loop control module is used for performing delta-sigma modulation on the difference value between the signal before LC filtering and the signal output by the outer loop control module and then outputting the difference value; a dead zone setting module for setting a long dead zone time; the driving logic signal output by the inner ring control module drives the switching tube in the bridge type inverter circuit after a long dead time, so that the switching frequency is reduced, the working mode of the switching tube is a mixed conduction mode or an intermittent mode, the switching tube can realize zero current switching-on and give consideration to larger system output power capacity, and the input alternating current signal is converted into a direct current signal and then is output. By setting and adjusting the long dead time, the soft switching of the power switching device is realized and high precision is realized without an additional resonant circuit.

Description

Alternating current switching power supply for realizing mixed conduction mode based on long dead time
Technical Field
The invention belongs to the field of switching power supplies, and particularly relates to an alternating current switching power supply for realizing a hybrid conduction mode based on long dead time.
Background
High-precision alternating current power supplies have important applications in the fields of precision manufacturing, precision measurement and medical treatment. delta-sigma modulation control can achieve good accuracy, but to achieve excellent accuracy performance, delta-sigma modulation is required to achieve low latency. The low time delay can cause very high switching frequency, and the performance of the existing switching device is limited, so that the switching device is not suitable for high-power occasions, and in addition, the problem of electromagnetic compatibility can be caused by the overhigh switching frequency. In order to reduce the switching frequency while ensuring accuracy, a common approach is to add a filter in the delta-sigma modulated sampling loop. The larger the filter, the lower the switching frequency, but the filter will reduce the sampling bandwidth and reduce the error rejection capability of the system in the middle frequency band, so that the available high precision bandwidth of the system is reduced. Furthermore, the manner of changing the filter to change the switching frequency has limited adjustability and is complicated to modify in engineering. Therefore, it is important to simply reduce the switching frequency while ensuring the accuracy and the system bandwidth.
In addition to the requirement of high precision, the more general requirement of the switching power supply is high efficiency, and soft switching is an effective way to achieve high efficiency. The current way of implementing soft switching usually requires peripheral auxiliary devices to implement resonance, which increases the complexity of control and design. Zero Current switching-on of a switching tube can be realized through inductive Current interruption, and an inverter in an interrupted Mode (DCM) does not need an auxiliary device, but a traditional inverter in the inductive Current interruption Mode usually adopts a Current hysteresis Mode and needs a large number of analog devices to realize control. In addition, since the voltage comparator cannot accurately detect the comparison voltage, the output waveform and control of the inverter are adversely affected. In addition, the state average model of the inverter of the conventional DCM is related to the duty ratio and the output voltage at the time in each switching period, and is a nonlinear and time-varying model, and because modeling is difficult, hysteresis control depends on trial and error, and a higher-level feedback control strategy is lacking. In summary, it is very important to make the switching power supply achieve high accuracy at a proper switching frequency, achieve high efficiency similar to that in the case of DCM, and facilitate modeling to achieve high-level control.
Disclosure of Invention
Aiming at the defects and the improvement requirements of the prior art, the invention provides an alternating current switching power supply for realizing a mixed conduction mode based on long dead time, and aims to realize soft switching and mixed conduction of a power switching device without an additional resonant circuit by setting and adjusting the long dead time.
In order to achieve the above object, the present invention provides an ac switching power supply for realizing a hybrid conduction mode based on a long dead time, comprising: the inverter module comprises a bridge inverter circuit and an LC filter circuit connected with the middle point of a bridge arm of the bridge inverter circuit; the outer ring control module is used for carrying out PID control on the LC filtered signals in the inversion module and then outputting the signals; the inner ring control module is used for performing delta-sigma modulation on a difference value between a signal before LC filtering in the inversion module and a signal output by the outer ring control module and then outputting a driving logic signal; the dead zone setting module is connected between the inner ring control module and the bridge inverter circuit and is used for setting long dead zone time, and the range of the long dead zone time is 5-500 mu s; and the driving logic signal output by the inner ring control module drives a switching tube in the bridge type inverter circuit after the long dead time, so that the working mode of the switching tube is a mixed conduction mode or an intermittent mode, and the input alternating current signal is converted into a direct current signal and then output.
Furthermore, the switching tube is reversely connected in parallel with a diode, and the dead zone setting module is used for increasing the long dead zone time, so that the inductance current in the LC filter circuit flows through the diode of the upper bridge arm or the lower bridge arm and is continuously reduced to zero in the long dead zone time, so as to control the switching tube to work in an intermittent mode and realize zero current switching-on.
Furthermore, the switch tube is reversely connected with a diode in parallel, and the dead zone setting module is also used for setting two types of long dead zone time with different sizes; the inductance current in the LC filter circuit is continuously reduced through the diode of the upper bridge arm or the lower bridge arm, the switch tube is conducted when the inductance current is not reduced to zero in a small long dead time, and the switch tube is conducted when the inductance current is reduced to zero in a large long dead time so as to control the switch tube to work in a mixed conduction mode.
Furthermore, the dead zone setting module is further configured to adjust the ratio of the two types of long dead zone times with different magnitudes, so as to adjust the ratio of continuous conduction and discontinuous conduction in the hybrid conduction mode.
Furthermore, the switch tube is reversely connected with a diode in parallel, and the dead zone setting module is also used for setting long dead zone time with fixed duration; in the switching process of the upper bridge arm switching tube and the lower bridge arm switching tube, the inductive current in the LC filter circuit is continuously reduced through the upper bridge arm diode or the lower bridge arm diode, if the inductive current is larger than a current threshold value, the switching tube is conducted when the inductive current is not reduced to zero, otherwise, the switching tube is conducted when the inductive current is reduced to zero, so that the switching tube is controlled to work in a mixed conduction mode.
Furthermore, the switch tube is reversely connected with a diode in parallel, and the dead zone setting module is further used for adjusting the long dead zone time, so that the long dead zone time is longer than the driving time of the switch tube, and the switch tube is kept turned off to reduce the turn-on and turn-off times of the switch tube.
Furthermore, the alternating current switching power supply is an alternating current voltage source, the alternating current voltage source further comprises a voltage sampling module, the voltage sampling module is used for sampling voltage signals filtered by the inverter module LC, and the outer ring control module is used for outputting the sampled voltage signals after PID control.
Furthermore, the alternating current switching power supply is an alternating current source, the alternating current source further comprises a current sampling module, the current sampling module is used for sampling current signals filtered by the inverter module LC, and the outer loop control module is used for outputting the sampled current signals after PID control.
Generally, by the above technical solution conceived by the present invention, the following beneficial effects can be obtained:
(1) the high-precision index of the alternating current switching power supply is realized by utilizing delta-sigma modulation, the precision is further improved by combining PID control, and on the basis, the soft switching and mixed conduction of a power switching device are realized by setting long dead time under the condition of not needing an additional resonant circuit, so that the high efficiency is realized; compared with a mode of increasing loop time delay in a delta-sigma inner loop and reducing switching frequency, the precision can be better ensured in a long dead time mode; in addition, the delta-sigma modulation model solves the problems that a mathematical model obtained according to a state equation under an inductive current discontinuous mode is nonlinear and time-varying and cannot be unified with the mathematical model under a continuous current mode in a mode of injecting an error source, so that the system is convenient to analyze and control, and an analysis basis is established for more advanced control;
(2) due to the existence of long dead time, the switching frequency is reduced, and the inductive current can be interrupted, so that zero current switching-on of the switching tube is realized, the loss of the switching tube is greatly reduced, and the efficiency of the whole machine is improved;
(3) due to the existence of two long dead time with different lengths, the switching frequency is reduced, and the inductive current can be interrupted or partially interrupted, so that the mixed conduction of the switching tube is realized, the peak value of the inductive current in the mixed conduction mode is smaller than that in the interrupted mode, and the current stress of a switching device and an inductor can be reduced, thereby reducing the inductive loss, the turn-off loss and the on-state loss of the switching tube;
(4) the switching tube is kept turned off by setting the long dead time to be longer than the given driving time of the switching tube, so that the turn-on and turn-off times of the switching tube can be reduced, and the loss of the switching tube is reduced.
Drawings
Fig. 1 is a schematic structural diagram of an ac switching voltage source for implementing a hybrid conduction mode based on a long dead time according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of an ac switching current source for implementing a hybrid conduction mode based on a long dead time according to an embodiment of the present invention;
FIG. 3 is a waveform diagram of delta-sigma + PID voltage dual-loop control provided by an embodiment of the invention;
FIG. 4 is a waveform diagram after adding loop delay under delta-sigma control;
FIG. 5 is a waveform diagram after increasing the dead time under delta-sigma control provided by an embodiment of the present invention;
fig. 6 is a waveform diagram after dead time is increased under the delta-sigma voltage inner loop PID current outer loop control provided by the embodiment of the present invention;
FIG. 7 is a waveform diagram of an output waveform with a high switching frequency caused by setting a lower time delay of an inner loop under delta-sigma + PID voltage double loop control;
fig. 8 is a detailed waveform diagram of a switching tube for realizing zero current turn-on after dead time is increased under delta-sigma control according to an embodiment of the present invention;
fig. 9 is a modulation model of delta-sigma modulation applied in an inverter according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
In the present application, the terms "first," "second," and the like (if any) in the description and the drawings are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.
Fig. 1 and fig. 2 are schematic structural diagrams of an ac switching voltage source and an ac switching current source for implementing a hybrid conduction mode based on a long dead time according to an embodiment of the present invention. Referring to fig. 1 and 2, an ac switching power supply for implementing a hybrid conduction mode based on a long dead time in this embodiment will be described in detail with reference to fig. 3 to 9.
The alternating current switching power supply for realizing the hybrid conduction mode based on the long dead time comprises an inversion module, an outer ring control module, an inner ring control module and a dead time setting module. The inverter module comprises a bridge inverter circuit and an LC filter circuit connected with the middle point of a bridge arm of the bridge inverter circuit, the bridge inverter circuit is used for converting an input direct current signal into an alternating current signal and then outputting the alternating current signal, and the LC filter circuit is used for performing LC filtering on the alternating current signal output by the bridge inverter circuit. And the outer ring control module is used for carrying out PID control on the LC filtered signals in the inverter module and then outputting the signals. And the inner ring control module is used for performing delta-sigma modulation on the difference value between the signal before LC filtering in the inversion module and the signal output by the outer ring control module and then outputting a driving logic signal. The dead zone setting module is connected between the inner ring control module and the bridge type inverter circuit, the input of the dead zone setting module is connected with the output of the inner ring control module, the output of the dead zone setting module is connected with a driving link for driving the bridge type inverter circuit, and the dead zone setting module is used for setting long dead zone time, and the range of the long dead zone time is 5-500 mu s. The driving logic signal output by the inner ring control module drives a switching tube in the bridge type inverter circuit after a long dead time, so that the working mode of the switching tube comprises a mixed conduction mode and/or an interrupted mode, and the input alternating current signal is converted into a direct current signal and then output.
In this embodiment, the dead time refers to a protection period set for preventing the upper and lower switching tubes of the bridge inverter circuit from being turned on simultaneously due to the switching speed problem when the inner loop control module outputs the driving logic signal, that is, the driving response time of the inner loop control module. It is understood that the long dead time in this embodiment may have other ranges as long as the duration of the long dead time is sufficient to make the operation mode of the switching tube be the mixed conduction mode or the discontinuous mode. In the alternating-current switching power supply in the embodiment, due to the feedback property of delta-sigma modulation, the switching frequency is forced to be reduced, and the inductor current is interrupted or partially interrupted due to the lower switching frequency, so that zero current switching-on of the switching tube is realized, and the loss of the switching tube is greatly reduced.
Each switching tube in the bridge inverter circuit is reversely connected with a diode in parallel, as shown in fig. 1 and fig. 2. It should be noted that, when the switching tube is an MOS tube, the body diode of the MOS tube may be directly used, and it is not necessary to additionally provide a diode connected in reverse parallel for the MOS tube; when the switch tube is an IGBT, the IGBT is usually integrated with an antiparallel diode, and the antiparallel diode does not need to be additionally provided for the IGBT. The control process of the alternating current switching power supply working in the discontinuous mode comprises the following steps: the dead zone setting module enlarges the long dead zone time, so that the inductance current in the LC filter circuit flows through the diode of the upper bridge arm or the lower bridge arm and is continuously reduced to zero in the long dead zone time, and the switching tube is controlled to work in an intermittent mode to realize zero current switching-on. The specific value of the long dead time is determined by the specific application scene, and only the requirement that the inductive current in the LC filter circuit can be reduced to zero is met.
The implementation process of inductor current interruption (discontinuous mode) is described by taking a half-bridge topology as an example. When the comparator in the inner ring control module acts, a corresponding switch tube driving logic signal is generated, the dead zone setting module sets a long-time dead zone, the switch tubes are all locked in the dead zone time, the inductive current flows through the diodes of the upper tube or the lower tube according to the direction, the inductive current is blocked and is continuously reduced in the dead zone time, when the dead zone time is long enough, the inductive current can be reduced to zero, and then the inductive current is maintained near zero until the comparator acts again and the new dead zone time is finished, so that the switch tubes are switched on when the current is zero, and the switching loss is reduced.
In an embodiment of the present invention, a control process of the ac switching power supply operating in the hybrid conduction mode includes: the dead zone setting module sets two types of long dead zone time with different sizes; the inductance current in the LC filter circuit is reduced continuously through the diode of the upper bridge arm or the lower bridge arm; in a small long dead time, the switching tube is conducted when the inductive current is not reduced to zero, namely the inductive current works in a continuous conduction mode; in a larger long dead time, the switching tube is conducted when the inductive current is reduced to zero, namely the inductive current works in a discontinuous conduction mode; therefore, the control switch tube works in a mixed conduction mode. The specific values of the two types of long dead time are determined by specific application scenarios, and only the requirement that the larger long dead time can reduce the inductive current in the LC filter circuit to zero and the smaller long dead time does not reduce the inductive current in the LC filter circuit to zero is met.
Further, the dead zone setting module may also adjust the ratio of continuous conduction and discontinuous conduction in the hybrid conduction mode by adjusting the ratio of the two types of long dead zone times that are not equal in magnitude (e.g., by adjusting the frequency of occurrence of the two types of long dead zone times).
In another embodiment of the present invention, the control process of the ac switching power supply operating in the hybrid conduction mode is as follows: the dead zone setting module sets a type of long dead zone time with fixed duration; in the switching process of the upper bridge arm switching tube and the lower bridge arm switching tube, inductance current in the LC filter circuit flows through the diode of the upper bridge arm or the lower bridge arm and is continuously reduced; if the inductive current is larger than the current threshold (for example, the inductive current is at the current peak), the switching tube is conducted when the inductive current is not reduced to zero, that is, the inductive current works in a continuous conduction mode; if the inductive current is not larger than the current threshold (for example, the inductive current is near zero current), the switching tube is conducted when the inductive current is reduced to zero, that is, the inductive current works in a discontinuous conduction mode; therefore, the control switch tube works in a mixed conduction mode. The current threshold is a value related to a specific application scenario, and is only used for explaining that when the upper and lower bridge arm switching tubes are switched, if the inductive current is larger at this time, the inductive current works in a continuous conduction mode, otherwise, the inductive current works in a discontinuous conduction mode, so that the hybrid conduction of the switching tubes is realized.
The implementation process of discontinuous + continuous (mixed conduction mode) of the inductor current is described by taking a half-bridge topology as an example. The implementation process of the inductor current interruption is the same as the implementation process of the inductor current interruption described above, and is not described again here; the continuous realization process of the inductive current comprises the following steps: when the inductive current is too large or the dead time is small, the inductive current is not reduced to zero and the switching tube is already conducted, so that the mixed conduction mode of intermittent current part is realized. The hybrid conduction mode has the advantage that the peak value of the inductor current is smaller than that in the discontinuous mode, so that the current stress of a switching device and an inductor can be reduced, and the inductor loss, the turn-off loss and the on-state loss of a switching tube are reduced. Therefore, a mixed conduction mode of a suitable ratio is more advantageous to achieve high efficiency.
According to the embodiment of the invention, the dead zone setting module is further used for adjusting the long dead zone time, so that the long dead zone time is longer than the driving time of the switching tube, and the switching tube is kept turned off to reduce the turn-on and turn-off times of the switching tube. Because the value of the inductive current is constantly reduced no matter the direction is in the dead zone period, the dead zone has the same effect as the corresponding control sequence blocking the inductive current, and because of the substitution, the dead zone time can exceed the driving time of the switch tube, the switch tube is kept to be turned off, and the turn-on and turn-off times of the switch tube are reduced, so that the loss of the switch tube is reduced.
In an embodiment of the present invention, the ac switching power supply is an ac voltage source, as shown in fig. 1. The alternating current voltage source further comprises a voltage sampling module, the voltage sampling module is used for sampling voltage signals filtered by the inverter module LC, and the outer ring control module is used for outputting the sampled voltage signals after PID control.
Specifically, referring to fig. 1, the ac voltage source includes a bridge inverter circuit, an LC filter circuit, a load, a sampling module, a voltage sampling module, an outer loop control module, an inner loop control module, a dead zone setting module, and a driving link. The voltage sampling module samples voltage signals which flow through two ends of a load after LC filtering; the outer ring control module subtracts the voltage signal sampled by the voltage sampling module from the input reference signal, performs PID adjustment and outputs the result; the sampling module samples a voltage signal of a midpoint of a bridge arm; the inner ring control module integrates and compares and converts a difference value between a signal output by the outer ring control module and a voltage signal sampled by the sampling module to obtain a driving logic signal; the dead zone setting module is used for setting a long-time dead zone, and driving logic signals pass through the long-time dead zone and then drive a switching tube in the bridge type inverter circuit through a driving link, so that the alternating current output by the bridge type inverter circuit is equal to a target alternating current.
In another embodiment of the present invention, the ac switching power supply is an ac current source, as shown in fig. 2. The alternating current source further comprises a current sampling module, the current sampling module is used for sampling current signals filtered by the inverter module LC, and the outer ring control module is used for outputting the sampled current signals after PID control.
Specifically, referring to fig. 2, the ac current source includes a bridge inverter circuit, an LC filter circuit, a load, a sampling module, a current sampling module, an outer loop control module, an inner loop control module, a dead zone setting module, and a driving link. The current sampling module samples current signals which flow through a load after LC filtering; the outer ring control module subtracts the current signal sampled by the current sampling module from the input reference signal, performs PID adjustment and outputs the result; the sampling module samples a voltage signal of a midpoint of a bridge arm; the inner ring control module integrates and compares and converts a difference value between a signal output by the outer ring control module and a voltage signal sampled by the sampling module to obtain a driving logic signal; the dead zone setting module is used for setting a long-time dead zone, and driving logic signals pass through the long-time dead zone and then drive a switching tube in the bridge type inverter circuit through a driving link, so that the alternating current output by the bridge type inverter circuit is equal to a target alternating current.
In the alternating-current switching power supply, a delta-sigma modulation model adopted by an inner loop control module is shown in fig. 9, K represents the equivalent gain of a loop integrator, and e-stThe model of the injection noise source is time domain, so the model is suitable for analyzing the state of the inverter in the discontinuous mode, thereby solving the problem that the mathematical model obtained according to the state equation in the discontinuous mode of the inductive current is nonlinear and time-varying and can not be unified with the mathematical model in the continuous current mode, facilitating the analysis and control of the system and establishing the analysis basis for the advanced control of PID and other controls.
Referring to FIG. 3, the output voltage u under delta-sigma + PID voltage dual loop control is shownoOutput current ioInductor current iLAnd the switching tube voltage uG1Experimental waveform diagram (c). In the waveform shown in fig. 3, the Total Harmonic Distortion (THD) is 0.287%, and the efficiency is 94.8%.
For delta-sigma control, loop time delay is increased, mixed conduction of inductive current is realized, and at the moment, output voltage u is outputoOutput current ioInductor current iLAnd the switching tube voltage uG1The experimental waveform of (2) is shown in FIG. 4. In the waveform diagram shown in fig. 4, the THD is only 1.09%, and the efficiency is 94.9%, which shows that the power supply precision is greatly affected by implementing the hybrid conduction mode in the long-delay mode.
For delta-sigma control, the long dead time provided in the embodiment is increased to realize inductor current mixed conduction, and at the moment, the output voltage u is outputoOutput current ioInductor current iLAnd the switching tube voltage uG1The experimental waveform of (2) is shown in fig. 5. In the waveform diagram shown in fig. 5, the THD is 0.432%, and the efficiency is 94.9%, and it can be seen that the long dead time mode in this embodiment can maintain high voltage source accuracy and high efficiency.
Comparing fig. 4 and fig. 5, it can be seen that, in implementing the same switching frequency, compared with increasing the loop delay to implement the inductor current interruption, the increase of the dead zone in the embodiment to implement the inductor current interruption can implement higher accuracy. Comparing fig. 3 and fig. 5, it can be seen that the delta-sigma + PID double-loop control can further improve the accuracy on the basis of realizing the discontinuity, thereby realizing the ac power supply with high accuracy and high efficiency.
Further, under the control of a delta-sigma voltage inner ring and a PID current outer ring, the long dead time provided in the embodiment is increased to realize the mixed conduction of the inductive current, and the output voltage u at the momentoOutput current ioInductor current iLAnd the switching tube voltage uG1The experimental waveform of (2) is shown in fig. 6. In the waveform diagram shown in fig. 6, the THD is 0.212%, and the efficiency is 94.8%, and it can be seen that the long dead time mode in this embodiment can realize an ac current source with high accuracy and high efficiency.
For the delta-sigma + PID voltage double-loop control shown in FIG. 3, the lower delay is added by the inner loop control, the output waveform is shown in FIG. 7, the average switching frequency in FIG. 7 is 90kHz, the high switching frequency is caused, and the voltage THD is 0.089%. In the results shown in fig. 7, the inductor current is mostly not interrupted due to the high switching frequency, and the switching tube is turned on hard, so that the efficiency is only 82.5%. Comparing fig. 6 and fig. 7, it can be seen that, in the embodiment, compared with the case that the delta-sigma + PID inner loop control adds a lower delay, the control of the delta-sigma + PID in the long dead time mode has the advantage of high efficiency, and the accuracy is still higher.
In addition, under delta-sigma control, the long dead time provided in the embodiment is increased to realize mixed conduction of the inductor and the current, and the output voltage u is output at the momentoOutput current ioInductor current iLAnd bridge arm midpoint voltage uG1The experimental waveform of the' is shown in fig. 8, and it can be seen that the interruption of the inductive current is realized, and the upper switching tube is switched on when the inductive current is zero, so that the zero-current switching-on is realized.
In the embodiment, because the delta-sigma modulation has the characteristic of noise shaping, various errors such as midpoint quantization of a bridge arm, dead zone effect and the like can be effectively inhibited, and thus the high-precision inverter power supply can be realized. The outer ring PID control module outputs voltage or current by sampling, thereby realizing a high-precision voltage source or current source. The dead zone setting module is used for reducing the switching frequency by setting a long-time dead zone, so that the interruption and/or partial interruption of the inductive current is realized, the switching loss is effectively reduced, and the conduction and turn-off times of the switching tube are reduced, so that the loss of the switching tube is reduced.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (8)

1. An alternating current switching power supply for realizing a hybrid conduction mode based on a long dead time, comprising:
the inverter module comprises a bridge inverter circuit and an LC filter circuit connected with the middle point of a bridge arm of the bridge inverter circuit;
the outer ring control module is used for carrying out PID control on the LC filtered signals in the inversion module and then outputting the signals;
the inner ring control module is used for performing delta-sigma modulation on a difference value between a signal before LC filtering in the inversion module and a signal output by the outer ring control module and then outputting a driving logic signal; the dead zone setting module is connected between the inner ring control module and the bridge inverter circuit and is used for setting long dead zone time, and the range of the long dead zone time is 5-500 mu s;
and the driving logic signal output by the inner ring control module drives a switching tube in the bridge type inverter circuit after the long dead time, so that the working mode of the switching tube is a mixed conduction mode or an intermittent mode, and the input alternating current signal is converted into a direct current signal and then output.
2. The alternating current switching power supply for realizing the hybrid conduction mode based on the long dead time as claimed in claim 1, wherein the switching tube is reversely connected with a diode in parallel, and the dead time setting module is used for increasing the long dead time, so that the inductance current in the LC filter circuit flows through the diode of the upper bridge arm or the lower bridge arm and is continuously reduced to zero in the long dead time, so as to control the switching tube to work in an intermittent mode and realize zero current switching-on.
3. The alternating current switching power supply for realizing the mixed conduction mode based on the long dead time as claimed in claim 1, wherein the switching tube is reversely connected with a diode in parallel, and the dead time setting module is further used for setting two types of long dead time with different sizes;
the inductance current in the LC filter circuit is continuously reduced through the diode of the upper bridge arm or the lower bridge arm, the switch tube is conducted when the inductance current is not reduced to zero in a small long dead time, and the switch tube is conducted when the inductance current is reduced to zero in a large long dead time so as to control the switch tube to work in a mixed conduction mode.
4. An alternating current switching power supply for realizing a hybrid conduction mode based on long dead time as claimed in claim 3, wherein said dead time setting module is further configured to adjust the ratio of said two types of long dead time with different sizes so as to adjust the ratio of continuous conduction and discontinuous conduction in said hybrid conduction mode.
5. An alternating current switching power supply for realizing a hybrid conduction mode based on a long dead time as claimed in claim 1, wherein the switching tube is reversely connected with a diode in parallel, and the dead time setting module is further used for setting the long dead time with a fixed duration;
in the switching process of the upper bridge arm switching tube and the lower bridge arm switching tube, the inductive current in the LC filter circuit is continuously reduced through the upper bridge arm diode or the lower bridge arm diode, if the inductive current is larger than a current threshold value, the switching tube is conducted when the inductive current is not reduced to zero, otherwise, the switching tube is conducted when the inductive current is reduced to zero, so that the switching tube is controlled to work in a mixed conduction mode.
6. An alternating current switching power supply for realizing a hybrid conduction mode based on a long dead time as claimed in claim 1, wherein the switching tube is reversely connected with a diode in parallel, the dead time setting module is further used for adjusting the long dead time, so that the long dead time is longer than the driving time of the switching tube, and the switching tube is kept turned off to reduce the turn-on and turn-off times of the switching tube.
7. The alternating current switching power supply for realizing the hybrid conduction mode based on the long dead time according to any one of claims 1 to 6, wherein the alternating current switching power supply is an alternating current voltage source, the alternating current voltage source further comprises a voltage sampling module, the voltage sampling module is configured to sample the voltage signal filtered by the inverter module LC, and the outer loop control module is configured to output the sampled voltage signal after PID control.
8. The alternating current switching power supply for realizing the hybrid conduction mode based on the long dead time according to any one of claims 1 to 6, wherein the alternating current switching power supply is an alternating current source, the alternating current source further comprises a current sampling module, the current sampling module is configured to sample the current signal LC-filtered by the inverter module, and the outer loop control module is configured to output the sampled current signal after PID control.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114123832A (en) * 2022-01-29 2022-03-01 华能平凉发电有限责任公司 Dead zone automatic compensation method and circuit based on IGBT

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101478256A (en) * 2008-09-17 2009-07-08 清华大学 Soft switch welding inverter, phase-shifting control method and soft switching method
CN105553306A (en) * 2016-01-19 2016-05-04 华中科技大学 Inversion power supply device in hybrid conduction mode and direct charge control method of inversion power supply device
CN111800031A (en) * 2020-07-15 2020-10-20 浙江昱能科技有限公司 Three-phase inverter and control method thereof
CN113078834A (en) * 2021-03-25 2021-07-06 华中科技大学 Inverter based on digital delta-sigma and PID double-loop control and design method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101478256A (en) * 2008-09-17 2009-07-08 清华大学 Soft switch welding inverter, phase-shifting control method and soft switching method
CN105553306A (en) * 2016-01-19 2016-05-04 华中科技大学 Inversion power supply device in hybrid conduction mode and direct charge control method of inversion power supply device
CN111800031A (en) * 2020-07-15 2020-10-20 浙江昱能科技有限公司 Three-phase inverter and control method thereof
CN113078834A (en) * 2021-03-25 2021-07-06 华中科技大学 Inverter based on digital delta-sigma and PID double-loop control and design method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
YONG QU等: "A Fully Soft Switched Point-of-Load Converter for Resource Constraint Drone Applications", 《IEEE TRANSACTIONS ON POWER ELECTRONICS》, vol. 35, no. 3, pages 2705 - 2713, XP011761779, DOI: 10.1109/TPEL.2019.2929164 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114123832A (en) * 2022-01-29 2022-03-01 华能平凉发电有限责任公司 Dead zone automatic compensation method and circuit based on IGBT
CN114123832B (en) * 2022-01-29 2022-04-22 华能平凉发电有限责任公司 Dead zone automatic compensation method and circuit based on IGBT

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