Current zero-crossing distortion control system and method based on totem-pole topological converter

Abstract

The invention discloses a current zero-crossing distortion control system and method based on a totem-pole topological converter, and relates to the technical field of power electronics. The system comprises: a control module comprising a voltage outer loop control unit and a current inner loop control unit; the voltage outer loop control unit is used for acquiring the actual output voltage and the rated bus voltage of the totem-pole topological converter, generating an input current reference value based on the actual output voltage and the rated bus voltage, and transmitting the input current reference value to the current inner loop control unit; the current inner loop control unit is used for acquiring an input current sampling value of the totem-pole topological converter and generating a modulation wave signal based on an input current reference value and the input current sampling value; and the driving module is used for receiving the modulation wave signal transmitted by the current inner loop control unit and generating a high-frequency driving signal of the high-frequency bridge arm switch tube and a power-frequency driving signal of the power-frequency bridge arm switch tube based on the modulation wave signal. According to the embodiment of the invention, the current zero-crossing distortion phenomenon can be effectively suppressed.

Description

Technical Field

[0001] The present application belongs to the field of power electronics technology, and in particular, relates to a current zero-crossing distortion control system and method based on a totem pole topology converter. Background Art

[0002] At present, totem pole topology converters and their variants have significant advantages in the field of power factor correction (PFC), especially in applications that require high efficiency and high power density. The traditional Si MOS tube (Silicon Metal-Oxide-Semiconductor Field-Effect Transistor) has poor body diode reverse recovery characteristics and high reverse recovery loss, which causes the totem pole topology converter to only work in current discontinuous mode, and the current harmonics and THD (Total Harmonic Distortion) are very large, which limits the application scenarios of totem pole topology converters.

[0003] As higher voltage wide band gap (WBG) semiconductor devices such as silicon carbide and gallium nitride begin to be studied, the totem pole topology converter combined with WBG devices has shown superior performance. Especially in the current continuous conduction mode, the totem pole topology converter working under hard switching conditions eliminates the reverse recovery problem of the high-frequency bridge arm switch tube, which effectively improves the efficiency and power level. However, when the totem pole topology converter is used as an AC / DC converter (Alternating Current / Direct Current Converter), the input current will be severely distorted when the AC input voltage passes through the zero point, resulting in the current waveform not being able to follow the input voltage well, thereby increasing the current harmonic content and reducing the system power factor.

[0004] Based on this, the industry is still in urgent need of a current zero-crossing distortion control solution based on a totem pole topology converter to effectively reduce the distortion of the waveform near the zero-crossing point, thereby achieving the purpose of reducing the current harmonic content and improving the system power factor. Summary of the invention

[0005] The embodiment of the present application provides a current zero-crossing distortion control system and method based on a totem pole topology converter, which can effectively reduce the distortion degree of the waveform near the zero-crossing point, thereby achieving the purpose of reducing the current harmonic content and improving the system power factor.

[0006] In a first aspect, an embodiment of the present application provides a current zero-crossing distortion control system based on a totem pole topology converter, the current zero-crossing distortion control system based on the totem pole topology converter comprises a totem pole topology converter, a control module and a drive module; the totem pole topology converter comprises a high-frequency bridge arm switch tube and an industrial frequency bridge arm switch tube;

[0007] The control module includes a voltage outer loop control unit and a current inner loop control unit;

[0008] The voltage outer loop control unit is used to obtain the actual output voltage and the rated bus voltage of the totem pole topology converter, and generate an input current reference value based on the actual output voltage and the rated bus voltage, and transmit the input current reference value to the current inner loop control unit;

[0009] The current inner loop control unit is used to obtain the input current sampling value of the totem pole topology converter, and generate a modulation wave signal based on the input current reference value and the input current sampling value;

[0010] The driving module is used to receive the modulation wave signal transmitted by the current inner loop control unit, and generate a high-frequency driving signal for the high-frequency bridge arm switch tube and an industrial frequency driving signal for the industrial frequency bridge arm switch tube based on the modulation wave signal.

[0011] In some possible implementations, the voltage outer loop control unit is specifically used to:

[0012] Compare the actual output voltage with the rated bus voltage to obtain a voltage error; and send the voltage error, the absolute value of the input voltage of the totem pole topology converter, and the reciprocal of the square of the root mean square value of the input voltage to a first proportional integral controller to obtain an input current reference value;

[0013] The current inner loop control unit is specifically used to: compare the input current reference value with the input current sampling value to obtain a current error signal; and send the current error signal to a proportional resonant controller or a second proportional integral controller to obtain a modulated wave signal.

[0014] In some possible implementations, the control module further includes a phase-locked loop unit;

[0015] The phase-locked loop unit is used to obtain the input voltage, perform phase-locking processing on the input voltage, obtain the AC input voltage phase of the input voltage, and transmit the AC input voltage phase to the current inner loop control unit;

[0016] The current inner loop control unit is used to generate a modulation wave signal based on an input current reference value, an input current sampling value and an AC input voltage phase.

[0017] In some possible implementations, the driving module includes a first driving unit and a second driving unit;

[0018] The first driving unit is used to perform pulse width modulation on the modulation wave signal to generate a high-frequency driving signal with a preset duty cycle; the second driving unit is used to perform zero-crossing comparison on the modulation wave signal to generate an industrial frequency driving signal.

[0019] In some possible implementations, the high-frequency bridge arm switch tube includes a high-frequency bridge arm upper switch tube and a high-frequency bridge arm lower switch tube;

[0020] The power frequency bridge arm switch tube comprises a power frequency bridge arm upper switch tube and a power frequency bridge arm lower switch tube;

[0021] The driving module also includes a first inverter and a second inverter;

[0022] An input end of the first inverter is electrically connected to an output end of the first driving unit, and a second end of the first inverter is electrically connected to a control end of any one of the high-frequency bridge arm upper switch tube and the high-frequency bridge arm lower switch tube;

[0023] The input end of the second inverter is electrically connected to the output end of the second driving unit, and the second end of the second inverter is electrically connected to the control end of any one of the upper switch tube of the power frequency bridge arm and the lower switch tube of the power frequency bridge arm.

[0024] In some possible implementations, the totem pole topology converter further includes an AC input terminal, an AC output terminal, a bus capacitor, a DC input terminal, and a DC output terminal;

[0025] The AC input terminal and the AC output terminal are used to connect to an AC voltage source, and the DC input terminal and the DC output terminal are used to connect to a load;

[0026] The AC input end is electrically connected to the midpoint of the bridge arm of the high-frequency bridge arm switch tube, and the AC output end is electrically connected to the midpoint of the bridge arm of the power frequency bridge arm switch tube;

[0027] The power frequency bridge arm switch tube is connected in parallel to both ends of the high frequency bridge arm switch tube, and the bus capacitor is connected in parallel to both ends of the power frequency bridge arm switch tube; the first pole of the bus capacitor is electrically connected to the DC input end, and the second pole of the bus capacitor is electrically connected to the DC output end;

[0028] The actual output voltage of the totem pole topology converter is the sampled voltage across the bus capacitor.

[0029] In some possible implementations, the totem pole topology converter further includes an inductor;

[0030] The first end of the inductor is electrically connected to the AC input end, and the second end of the inductor is electrically connected to the midpoint of the bridge arm of the high-frequency bridge arm switch tube;

[0031] The input current sampling value of the totem pole topology converter is a sampling current value of the second end of the inductor.

[0032] In some possible implementations, the totem pole topology converter further includes a relay and a thermistor;

[0033] The relay and the thermistor are connected in parallel; the first end of the relay is electrically connected to the AC input end, and the second end of the relay is electrically connected to the first end of the inductor;

[0034] Among them, relays and thermistors are used to realize the soft start of the totem pole topology converter.

[0035] Based on the same inventive concept, in a second aspect, an embodiment of the present application provides a current zero-crossing distortion control method based on a totem pole topology converter; the totem pole topology converter includes a high-frequency bridge arm switch tube and an industrial frequency bridge arm switch tube; the current zero-crossing distortion control method based on the totem pole topology converter includes:

[0036] Obtaining the actual output voltage, rated bus voltage and input current sampling values ​​of the totem pole topology converter;

[0037] Generate an input current reference value based on the actual output voltage and the rated bus voltage;

[0038] Generate a modulation wave signal based on an input current reference value and an input current sampling value;

[0039] A high-frequency driving signal for the high-frequency bridge arm switch tube and an industrial frequency driving signal for the industrial frequency bridge arm switch tube are generated respectively based on the modulation wave signal.

[0040] In some possible implementations, generating an input current reference value based on the actual output voltage and the rated bus voltage includes:

[0041] The actual output voltage is compared with the rated bus voltage to obtain a voltage error; the voltage error, the absolute value of the input voltage of the totem pole topology converter and the reciprocal of the square of the root mean square value of the input voltage are sent to a first proportional integral controller to obtain an input current reference value;

[0042] A modulation wave signal is generated based on an input current reference value and an input current sampling value, including:

[0043] The input current reference value and the input current sampling value are compared to obtain a current error signal; and the current error signal is sent to a proportional resonant controller or a second proportional integral controller to obtain a modulated wave signal.

[0044] In a third aspect, an embodiment of the present application provides a product recommendation device, the product recommendation device comprising:

[0045] a processor and a memory storing computer program instructions;

[0046] When the processor executes the computer program instructions, the product recommendation method provided in any one of the above-mentioned embodiments of the present application is implemented.

[0047] In a fourth aspect, an embodiment of the present application provides a computer storage medium having computer program instructions stored thereon, and when the computer program instructions are executed by a processor, a product recommendation method as provided in any one of the above-mentioned embodiments of the present application is implemented.

[0048] In a fifth aspect, an embodiment of the present application provides a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device executes a product recommendation method provided in any one of the above-mentioned embodiments of the present application.

[0049] The embodiment of the present application provides a current zero-crossing distortion control system and method based on a totem pole topology converter, in which a voltage outer loop control unit is provided to generate an input current reference value according to the actual output voltage and rated bus voltage of the totem pole topology converter, and the reference value is used as a given current inner loop control unit. The current inner loop control unit can generate a modulation wave signal according to the input current sampling value and the input current reference value of the totem pole topology converter. In this way, the driving module generates a high-frequency driving signal for the high-frequency bridge arm switch tube and an industrial frequency driving signal for the industrial frequency bridge arm switch tube according to the received modulation wave signal transmitted by the current inner loop control unit.

[0050] It can be known from the above description that a current zero-crossing distortion control system and method based on a totem pole topology converter according to an embodiment of the present application, since all gate signals of the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube are generated based on the modulation wave signal output by the current inner loop control unit, the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube can be synchronously switched based on the same modulation wave, so the phase delay and current spike of the totem pole topology converter when crossing the zero point will be effectively suppressed. In other words, since all gate signals of the switch tube are based on the control loop output of the current inner loop, the phase delay and current spike will be effectively suppressed. By adopting the current zero-crossing distortion control system and method based on the totem pole topology converter according to an embodiment of the present application, the degree of distortion of the waveform near the zero point can be effectively reduced, thereby achieving the purpose of reducing the current harmonic content and improving the system power factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0052] Figure 1It is an equivalent model of the totem pole topology converter provided in the embodiment of the present application;

[0053] Figure 2 It is a vector diagram of input voltage, current and bridge arm midpoint voltage provided in an embodiment of the present application;

[0054] Figure 3 It is a structural schematic diagram of a current zero-crossing distortion control system based on a totem pole topology converter provided in an embodiment of the present application;

[0055] Figure 4 It is another structural schematic diagram of a current zero-crossing distortion control system based on a totem pole topology converter provided in an embodiment of the present application;

[0056] Figure 5 It is another structural schematic diagram of a current zero-crossing distortion control system based on a totem pole topology converter provided in an embodiment of the present application;

[0057] Figure 6 It is another structural schematic diagram of a current zero-crossing distortion control system based on a totem pole topology converter provided in an embodiment of the present application;

[0058] Figure 7 It is another structural schematic diagram of a current zero-crossing distortion control system based on a totem pole topology converter provided in an embodiment of the present application;

[0059] Figure 8 It is a flow chart of a current zero-crossing distortion control method based on a totem pole topology converter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0060] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0061] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0062] In the embodiments of the present application, the term “electrically connected” may refer to a direct electrical connection between two components, or may refer to an electrical connection between two components via one or more other components.

[0063] It is obvious to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit or scope of the present application. Therefore, the present application is intended to cover modifications and changes of the present application that fall within the scope of the corresponding claims (technical solutions for protection) and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present application can be combined with each other without contradiction.

[0064] As described in the background technology section, when a totem pole topology converter is currently used as an AC / DC converter, the input current will be severely distorted when the AC input voltage passes through the zero point, causing the current waveform to be unable to follow the input voltage well, thereby increasing the current harmonic content and reducing the system power factor.

[0065] After careful research by the inventor of this application, it is found that there are many reasons for the current distortion when the voltage passes through zero. One of the reasons is the phase delay between the input voltage at the midpoint of the bridge arm and the AC input voltage of the power grid caused by the power inductor. Figure 1 and Figure 2 , Figure 1 It is an equivalent model of the totem pole topology converter provided in the embodiment of the present application; Figure 2 : is a vector diagram of input voltage, current and bridge arm midpoint voltage provided by the embodiment of the present application. Figure 2 As shown, when the AC voltage passes through the inductor, it will cause the input voltage V abThe conventional control method often uses the grid voltage zero crossing obtained by sampling as the switching signal of the power frequency bridge arm, while ignoring the influence of the power inductance. In this way, the high-frequency bridge arm switching signal and the power frequency bridge arm switching signal cannot switch synchronously at the zero crossing point, resulting in current distortion at the zero crossing point.

[0066] Some solutions have been proposed in the prior art for the above-mentioned zero-crossing distortion problem, such as: (1) When the AC voltage passes through zero, a switch duty cycle soft start method is used. However, although this solution can alleviate the current spike when the voltage passes through zero, the implementation of this solution is cumbersome, and the current at the voltage zero crossing is sacrificed, which reduces the power factor value of the converter. (2) Reducing zero-crossing distortion through current prediction control: The current spike value at the zero crossing point in the previous few cycles is obtained through sampling, and then the current reference value is reversely compensated according to the sampled data, so that the current follows the reference value in the opposite direction when passing through zero to offset the original current spike. However, although this solution can reduce the current zero-crossing spike to a certain extent, its controller requires more precise sampling accuracy and a higher sampling period, and has weak anti-interference ability, which will put great pressure on the hardware cost and software calculation.

[0067] The above-mentioned control schemes for suppressing AC current distortion when AC voltage passes through zero, such as digital soft start, adding external circuits, etc., mostly rely on cumbersome control strategies, or rely on sampling circuits with high precision. These schemes have problems such as cumbersome control, high hardware cost, low reliability, and susceptibility to interference. Therefore, how to provide a current zero-crossing distortion control scheme that is simple to implement, cost-saving, and can reduce the amount of program calculations, and the control effect is less affected by sampling interference, so as to effectively reduce the distortion of the waveform near the zero-crossing point, thereby achieving the purpose of reducing the current harmonic content and improving the system power factor, is of great significance to the widespread application of the current totem pole topology converter.

[0068] In view of the above, in order to solve the problems of the prior art, the embodiments of the present application provide a current zero-crossing distortion control system and method based on a totem pole topology converter. It should be noted that the embodiments provided in the present application are not intended to limit the scope of the present application.

[0069] The following first introduces the current zero-crossing distortion control system based on the totem pole topology converter provided in the embodiment of the present application.

[0070] Figure 3 FIG. 1 shows a schematic diagram of a current zero-crossing distortion control system based on a totem pole topology converter provided in an embodiment of the present application. Figure 3 As shown, the current zero-crossing distortion control system 1000 based on the totem pole topology converter in the embodiment of the present application includes a totem pole topology converter 100, a control module 200 and a driving module.

[0071] The totem pole topology converter 100 includes a high-frequency bridge arm switch tube and an industrial frequency bridge arm switch tube. Specifically, the high-frequency bridge arm switch tube may include a high-frequency bridge arm upper switch tube Q1 and a high-frequency bridge arm lower switch tube Q2, and the industrial frequency bridge arm switch tube may include an industrial frequency bridge arm upper switch tube S1 and an industrial frequency bridge arm lower switch tube S2, thereby forming a bridge arm circuit.

[0072] The control module 200 may specifically include a voltage outer loop control unit 10 and a current inner loop control unit 20 .

[0073] The voltage outer loop control unit 10 is used to obtain the actual output voltage V of the totem pole topology converter 100. dc and rated bus voltage V dc_ref , and based on the actual output voltage V dc and rated bus voltage V dc_ref Generate input current reference value I ref , the input current reference value I ref Transmitted to the current inner loop control unit 20.

[0074] The current inner loop control unit 20 is used to obtain the input current sampling value I of the totem pole topology converter 100. L , and based on the input current reference value I ref And the input current sampling value I L Generates a modulated wave signal.

[0075] It should be added that the actual output voltage V of the totem pole topology converter 100 is dc And the input current sampling value I L The acquisition of the above parameters can be achieved by setting corresponding voltage samplers and current samplers (such as Hall effect sensors, current transformers, etc.).

[0076] The above rated bus voltage V dc_ref It may be a reference bus voltage given by the totem pole topology converter 100 , which may be obtained through external input or pre-storage, and this embodiment does not impose strict restrictions on this.

[0077] The driving module 300 is used to receive the modulation wave signal transmitted by the current inner loop control unit 20, and generate a high-frequency driving signal for the high-frequency bridge arm switch tube and an industrial frequency driving signal for the industrial frequency bridge arm switch tube based on the modulation wave signal.

[0078] The embodiment of the present application provides a current zero-crossing distortion control system 1000 based on a totem pole topology converter 100, in which a voltage outer loop control unit 10 is provided to control the actual output voltage V of the totem pole topology converter 100 according to the actual output voltage V dc and rated bus voltage V dc_refGenerate input current reference value I ref , and use it as the current inner loop control unit 20. The current inner loop control unit 20 can be based on the input current sampling value I L Thus, the driving module 300 generates a high-frequency driving signal for the high-frequency bridge arm switch tube and an industrial frequency driving signal for the industrial frequency bridge arm switch tube according to the received modulated wave signal transmitted by the current inner loop control unit 20 .

[0079] From the above description, it can be seen that in an embodiment of the present application, a current zero-crossing distortion control system 1000 based on a totem pole topology converter 100, since all gate signals of the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube are generated based on the modulation wave signal output by the current inner loop control unit 20, the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube can be synchronously switched based on the same modulation wave, so the phase delay and current spike of the totem pole topology converter 100 when crossing the zero point will be effectively suppressed.

[0080] That is to say, since all gate signals of the switch tube are based on the control loop output of the current inner loop, phase delay and current spikes will be effectively suppressed. Therefore, by adopting the current zero-crossing distortion control system 1000 based on the totem pole topology converter 100 of the embodiment of the present application, the distortion degree of the waveform near the zero-crossing point can be effectively reduced, thereby achieving the purpose of reducing the current harmonic content and improving the system power factor.

[0081] According to some embodiments of the present application, optionally, in order to more reasonably determine the given value of the current inner loop control unit 20, the voltage outer loop control unit 10 may be specifically used to:

[0082] The actual output voltage V dc and rated bus voltage V dc_ref Compare and obtain the voltage error V err And, the voltage error V err , the input voltage V of the totem pole topology converter 100 ac The absolute value of the input voltage V ac The inverse of the square of the RMS value is sent to the first proportional-integral controller (PI controller) to obtain the input current reference value I ref .

[0083] In order to obtain a more reliable modulation wave, so as to realize the driving control of the high-frequency bridge arm switch tube and the power frequency bridge arm switch tube more accurately in the subsequent process, the current inner loop control unit 20 can be specifically used to: ref And the input current sampling value IL Comparison is performed to obtain a current error signal, and the current error signal is sent to a proportional resonant controller (PR controller) or a second proportional integral controller to obtain a modulation wave signal.

[0084] Please continue to see Figure 3 According to some embodiments of the present application, more specifically, the totem pole topology converter 100 may further include an AC input terminal, an AC output terminal, a bus capacitor Cbus, a DC input terminal and a DC output terminal.

[0085] The AC input and output terminals are used to connect to the AC voltage source AC, and the DC input and output terminals are used to connect to the load R1. The AC input terminal is electrically connected to the bridge arm midpoint N1 of the high-frequency bridge arm switch tube, and the AC output terminal is electrically connected to the bridge arm midpoint N2 of the power frequency bridge arm switch tube.

[0086] The power frequency bridge arm switch tube is connected in parallel at both ends of the high frequency bridge arm switch tube, and the bus capacitor Cbus is connected in parallel at both ends of the power frequency bridge arm switch tube. The first pole of the bus capacitor Cbus is electrically connected to the DC input end, and the second pole of the bus capacitor Cbus is electrically connected to the DC output end.

[0087] The actual output voltage V of the totem pole topology converter 100 is dc is the sampled voltage across the bus capacitor Cbus.

[0088] According to some embodiments of the present application, optionally, considering that the power inductor often causes a phase delay between the bridge arm midpoint input voltage and the grid AC input voltage, therefore, in order to effectively ensure the input current sampling value I of the totem pole topology converter 100 obtained L In order to improve reliability, the totem pole topology converter 100 may further include an inductor L.

[0089] The first end of the inductor L is electrically connected to the AC input end, and the second end of the inductor L is electrically connected to the bridge arm midpoint N1 of the high-frequency bridge arm switch tube. The input current sampling value I L is the sampling current value of the second end of the inductor L.

[0090] In this way, the current at the second end of the inductor L is collected and used as the input current sampling value I L The modulation wave is input to the current inner loop control unit 20 for modulation wave calculation, so as to fully guarantee the validity and reliability of the modulation wave output by the current inner loop control unit 20, which is beneficial to ensure the reliable driving of the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube while fully suppressing the current zero-crossing distortion.

[0091] Figure 4 Another structural schematic diagram of a current zero-crossing distortion control system 1000 based on a totem pole topology converter 100 provided in an embodiment of the present application is shown. Figure 4 As shown, in order to fully guarantee the reliability of the phase of the modulated wave signal, according to some embodiments of the present application, optionally, the control module 200 may further include a phase-locked loop 30 unit.

[0092] The phase-locked loop 30 unit is used to obtain the input voltage V ac , and the input voltage V ac Perform phase-locking processing to obtain the input voltage V ac The AC input voltage phase is transmitted to the current inner loop control unit 20.

[0093] The current inner loop control unit 20 can be used to calculate the current reference value I based on the input current. ref , input current sampling value I L And the AC input voltage phase generates a modulated wave signal.

[0094] In this embodiment, the phase-locked loop 30 is used to perform phase-locking processing on the input voltage Vac of the totem pole topology converter 100, so that the current inner loop controller can combine the input voltage V ac The modulated wave signal is output according to the AC input voltage phase, thereby effectively avoiding the signal phase deviation caused by the power voltage, and further ensuring the reliable driving of the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube while suppressing the current zero-crossing distortion.

[0095] See below Figure 5 , Figure 5 FIG. 1 shows another structural schematic diagram of a current zero-crossing distortion control system 1000 based on a totem pole topology converter 100 provided in an embodiment of the present application. Figure 5 As shown, according to some embodiments of the present application, optionally, in order to more accurately realize the drive control of the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube, the above-mentioned drive module 300 may include a first drive unit 40 and a second drive unit 50.

[0096] The first driving unit 40 is used to perform pulse width modulation (PWM) on the modulated wave signal to generate a high-frequency driving signal with a preset duty cycle. The second driving unit 50 is used to perform zero-crossing comparison on the modulated wave signal to generate an industrial frequency driving signal.

[0097] In this way, according to the different working requirements of the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube, the modulation wave signal is processed in a targeted manner through the above-mentioned first driving unit 40 and the second driving unit 50, so as to facilitate the effective AC / DC conversion work of the totem pole topology converter 100.

[0098] Please continue to see Figure 5 According to some embodiments of the present application, optionally, considering that the upper switch tube and the lower switch tube in the bridge arm circuit often have opposite driving characteristics, in order to efficiently drive different switch tubes in the bridge arm,

[0099] The driving module 300 may further include a first inverter K1 and a second inverter K2. The high-frequency bridge arm switch tube may include a high-frequency bridge arm upper switch tube Q1 and a high-frequency bridge arm lower switch tube Q2. The power frequency bridge arm switch tube may include a power frequency bridge arm upper switch tube S1 and a power frequency bridge arm lower switch tube S2.

[0100] The input end of the first inverter K1 is electrically connected to the output end of the first driving unit 40 , and the second end of the first inverter K1 is electrically connected to the control end of any one of the high-frequency bridge arm upper switch tube Q1 and the high-frequency bridge arm lower switch tube Q2 .

[0101] The input end of the second inverter K2 is electrically connected to the output end of the second driving unit 50 , and the second end of the second inverter K2 is electrically connected to the control end of any one of the upper switch tube S1 of the power frequency bridge arm and the lower switch tube S2 of the power frequency bridge arm.

[0102] It should be added that Figure 5 The situation in which the first inverter K1 and the second inverter K2 are both located at the switch tube under the bridge arm is shown, but in some other embodiments, the first inverter K1 and the second inverter K2 can also be arranged at the position of the switch tube on the bridge arm, and the present application does not impose strict restrictions on this.

[0103] See below Figure 6 , Figure 6 Another structural schematic diagram of a current zero-crossing distortion control system 1000 based on a totem pole topology converter 100 provided in an embodiment of the present application is shown. According to some embodiments of the present application, optionally, the totem pole topology converter 100 may further include a relay S and a thermistor R2. The thermistor R2 may specifically be, for example, an NTC thermistor (Negative Temperature Coefficient Thermistor) having a negative temperature coefficient.

[0104] like Figure 6As shown, the relay S and the thermistor R2 are connected in parallel. When specifically connected, the first end of the relay S is electrically connected to the AC input end, and the second end of the relay S is electrically connected to the first end of the inductor L; and the first end of the thermistor R2 is electrically connected to the AC input end, and the second end of the thermistor R2 is electrically connected to the first end of the inductor L.

[0105] The relay S and the thermistor R2 can be used to achieve soft start of the totem pole topology converter 100 .

[0106] Specifically, when the totem pole topology converter 100 is initially started, the relay S is disconnected to connect the thermistor R2 , thereby fully ensuring the safety of the components in the totem pole topology converter 100 through soft start.

[0107] After the totem pole topology converter 100 operates stably, the relay S is closed again to short-circuit the thermistor R2 , thereby maintaining the efficient and stable operation of the totem pole topology converter 100 .

[0108] Please refer to Figure 6 In some possible implementations, a notch filter may also be provided in the current zero-crossing distortion control system 1000 .

[0109] like Figure 6 As shown, the actual output voltage V of the totem pole topology converter 100 is obtained by sampling or the like. dc Afterwards, the actual output voltage V dc The voltage after filtering is sent to the notch filter for filtering, and then the filtered voltage is sent to the voltage outer loop control unit 10, so that the voltage outer loop control unit 10 can generate a more accurate input current reference value I ref .

[0110] In order to fully understand the current zero-crossing distortion control system 1000 based on the totem pole topology converter 100 shown in the embodiment of the present application, it is introduced in combination with a specific scenario below. Figure 7 , Figure 7 Another structural schematic diagram of a current zero-crossing distortion control system 1000 based on a totem pole topology converter 100 provided in an embodiment of the present application is shown.

[0111] like Figure 7 As shown, when the current zero-crossing distortion control is performed, the actual output voltage V of the totem pole topology converter 100 is collected by a corresponding voltage sampling device. dc The actual output voltage V after filtering by the notch filter dc The rated bus voltage V dc_ref Compare and obtain the voltage error Verr .

[0112] The input voltage V of the totem pole topology converter 100 is obtained by using a corresponding voltage sampling device. ac , and then sent to the phase-locked loop to obtain the AC input voltage phase. ac The absolute value of the voltage error V err And the input voltage V ac The inverse of the square of the RMS value is sent to the PI controller to obtain the input current reference value I ref .

[0113] The input current of the totem pole topology converter 100 is sampled by a corresponding current sampling device to obtain an input current sampling value I L The input current reference value I output by the aforementioned PI controller is ref With the input current sampling value I L By comparison, the current error signal I err . The current error signal I err After being sent to the PR controller, a modulated wave signal is obtained, and then the modulated wave signal is sent to the PWM module (the aforementioned first driving unit) to generate a preset duty cycle D, which is used to drive the high-frequency bridge arm switch tube of the totem pole topology converter 100. And, by performing a zero crossing comparison on the modulated wave signal, the switch tube used to drive the power frequency bridge arm is replaced with the polarity judgment signal of the power frequency bridge arm switch tube by the judgment of whether the modulated wave signal crosses zero.

[0114] In this embodiment, the control part of the totem pole topology converter 100 is mainly composed of a voltage and current dual closed-loop controller and a current zero-crossing distortion optimization control. It is specifically based on the rated bus voltage designed by the system as a reference for the voltage outer loop. The voltage outer loop generates a current inner loop reference given through a PI controller based on the bus voltage reference and bus voltage feedback. The current inner loop generates a modulation wave signal through a PR controller based on the reference given value of the input current and the actual feedback value of the input current. On the one hand, the modulation wave signal generates a high-frequency drive signal with a preset duty cycle through PWM modulation to control the on and off of the high-frequency bridge arm switch tube, and on the other hand, it controls the on and off of the power frequency bridge arm switch tube according to whether it crosses the zero point. In this way, since the gate signals of the high-frequency bridge arm and the power frequency bridge are based on the control loop output of the current inner loop, the phase delay and current spikes will be effectively suppressed.

[0115] Based on the same inventive concept, the embodiment of the present application provides a current zero-crossing distortion control method based on a totem pole topology converter. Similar to the above embodiment, the totem pole topology converter includes a high-frequency bridge arm switch tube and an industrial frequency bridge arm switch tube.

[0116] See below Figure 8 , Figure 81 is a flow chart of a current zero-crossing distortion control method based on a totem pole topology converter provided in an embodiment of the present application. Figure 8 As shown, the current zero-crossing distortion control method based on the totem pole topology converter includes:

[0117] S810, obtaining actual output voltage, rated bus voltage and input current sampling values ​​of the totem pole topology converter;

[0118] S820, generating an input current reference value based on the actual output voltage and the rated bus voltage;

[0119] S830, generating a modulation wave signal based on the input current reference value and the input current sampling value;

[0120] S840, generating a high-frequency driving signal for the high-frequency bridge arm switch tube and an industrial frequency driving signal for the industrial frequency bridge arm switch tube based on the modulation wave signal.

[0121] The embodiment of the present application provides a current zero-crossing distortion control method based on a totem pole topology converter, which generates an input current reference value according to the actual output voltage and rated bus voltage of the totem pole topology converter, and then generates a modulation wave signal according to the input current sampling value and the input current reference value of the totem pole topology converter. In this way, a high-frequency driving signal of a high-frequency bridge arm switch tube and an industrial frequency driving signal of an industrial frequency bridge arm switch tube are generated respectively according to the modulation wave signal transmitted by the received current inner loop control unit.

[0122] From the above description, it can be seen that an embodiment of the present application is a current zero-crossing distortion control method based on a totem pole topology converter. Since all gate signals of the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube are generated based on the same modulation wave signal, the high-frequency bridge arm switch tube and the industrial frequency bridge arm switch tube can achieve synchronous switching based on the same modulation wave. Therefore, the phase delay and current spike of the totem pole topology converter when crossing the zero point will be effectively suppressed.

[0123] That is to say, since all gate signals of the switch tube are based on the control loop output of the current inner loop, phase delay and current spikes will be effectively suppressed. By adopting the current zero-crossing distortion control method based on the totem pole topology converter of the embodiment of the present application, the distortion degree of the waveform near the zero-crossing point can be effectively reduced, thereby achieving the purpose of reducing the current harmonic content and improving the system power factor.

[0124] It should be understood that, for the sake of brevity, the specific implementation process of the above steps 810 to 840 can refer to the corresponding description part above, and this embodiment will not be repeated here.

[0125] According to some embodiments of the present application, optionally, generating an input current reference value based on the actual output voltage and the rated bus voltage includes:

[0126] The actual output voltage is compared with the rated bus voltage to obtain a voltage error; the voltage error, the absolute value of the input voltage of the totem pole topology converter and the reciprocal of the square of the root mean square value of the input voltage are sent to a first proportional integral controller to obtain an input current reference value;

[0127] A modulation wave signal is generated based on an input current reference value and an input current sampling value, including:

[0128] The input current reference value and the input current sampling value are compared to obtain a current error signal; and the current error signal is sent to a proportional resonant controller or a second proportional integral controller to obtain a modulated wave signal.

[0129] It should be understood here that, for the sake of brevity, the specific implementation process of the above steps can refer to the corresponding description part of the previous text, and this embodiment will not be repeated here.

[0130] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0131] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0132] It should be clear that each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. According to the embodiments described above in this application, these embodiments do not describe all the details in detail, nor do they limit the application to only the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that technicians in the relevant technical field can make good use of the application and the modified use based on the application. The application is only limited by the claims and their full scope and equivalents.

[0133] This article uses specific examples to illustrate the principles and implementation methods of this application. The above examples are only used to help understand the methods and core ideas of this application. The above are only preferred implementation methods of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concepts and technical solutions of this application to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A current zero-crossing distortion control system based on a totem pole topology converter. It is characterized in that The system includes the totem pole topology converter, a control module and a drive module; the totem pole topology converter includes a high-frequency bridge arm switch tube and an industrial frequency bridge arm switch tube; The control module includes a voltage outer loop control unit and a current inner loop control unit; The voltage outer loop control unit is used to obtain the actual output voltage and the rated bus voltage of the totem pole topology converter, and generate an input current reference value based on the actual output voltage and the rated bus voltage, and transmit the input current reference value to the current inner loop control unit; The current inner loop control unit is used to obtain the input current sampling value of the totem pole topology converter, and generate a modulation wave signal based on the input current reference value and the input current sampling value; The driving module is used to receive the modulation wave signal transmitted by the current inner loop control unit, and generate a high-frequency driving signal for the high-frequency bridge arm switch tube and an industrial frequency driving signal for the industrial frequency bridge arm switch tube based on the modulation wave signal.

2. The current zero-crossing distortion control system according to claim 1, It is characterized in that The voltage outer loop control unit is specifically used for: Comparing the actual output voltage with the rated bus voltage to obtain a voltage error; and sending the voltage error, the absolute value of the input voltage of the totem pole topology converter, and the reciprocal of the square of the root mean square value of the input voltage to a first proportional integral controller to obtain the input current reference value; The current inner loop control unit is specifically used to: compare the input current reference value with the input current sampling value to obtain a current error signal; and send the current error signal to a proportional resonant controller or a second proportional integral controller to obtain the modulated wave signal.

3. The current zero-crossing distortion control system according to claim 2, It is characterized in that The control module also includes a phase-locked loop unit; The phase-locked loop unit is used to obtain the input voltage, perform phase-locking processing on the input voltage, obtain the AC input voltage phase of the input voltage, and transmit the AC input voltage phase to the current inner loop control unit; The current inner loop control unit is used to generate the modulation wave signal based on the input current reference value, the input current sampling value and the AC input voltage phase.

4. The current zero-crossing distortion control system according to claim 1, It is characterized in that The driving module includes a first driving unit and a second driving unit; The first driving unit is used to perform pulse width modulation on the modulated wave signal to generate the high-frequency driving signal with a preset duty cycle; the second driving unit is used to perform zero-crossing comparison on the modulated wave signal to generate the industrial frequency driving signal.

5. The current zero-crossing distortion control system according to claim 4, It is characterized in that The high-frequency bridge arm switch tube comprises a high-frequency bridge arm upper switch tube and a high-frequency bridge arm lower switch tube; The power frequency bridge arm switch tube comprises a power frequency bridge arm upper switch tube and a power frequency bridge arm lower switch tube; The driving module further includes a first inverter and a second inverter; The input end of the first inverter is electrically connected to the output end of the first driving unit, and the second end of the first inverter is electrically connected to the control end of any one of the high-frequency bridge arm upper switch tube and the high-frequency bridge arm lower switch tube; The input end of the second inverter is electrically connected to the output end of the second driving unit, and the second end of the second inverter is electrically connected to the control end of any one of the upper switch tube of the power frequency bridge arm and the lower switch tube of the power frequency bridge arm.

6. The current zero-crossing distortion control system according to claim 1, It is characterized in that The totem pole topology converter also includes an AC input terminal, an AC output terminal, a bus capacitor, a DC input terminal and a DC output terminal; The AC input terminal and the AC output terminal are used to connect to an AC voltage source, and the DC input terminal and the DC output terminal are used to connect to a load; The AC input end is electrically connected to the midpoint of the bridge arm of the high-frequency bridge arm switch tube, and the AC output end is electrically connected to the midpoint of the bridge arm of the power frequency bridge arm switch tube; The power frequency bridge arm switch tube is connected in parallel to both ends of the high frequency bridge arm switch tube, and the bus capacitor is connected in parallel to both ends of the power frequency bridge arm switch tube; the first pole of the bus capacitor is electrically connected to the DC input end, and the second pole of the bus capacitor is electrically connected to the DC output end; The actual output voltage of the totem pole topology converter is a sampled voltage across the bus capacitor.

7. The current zero-crossing distortion control system according to claim 6, It is characterized in that The totem pole topology converter further comprises an inductor; The first end of the inductor is electrically connected to the AC input end, and the second end of the inductor is electrically connected to the midpoint of the bridge arm of the high-frequency bridge arm switch tube; The input current sampling value of the totem pole topology converter is a sampling current value of the second end of the inductor.

8. The current zero-crossing distortion control system according to claim 7, It is characterized in that The totem pole topology converter also includes a relay and a thermistor; The relay and the thermistor are connected in parallel; a first end of the relay is electrically connected to the AC input end, and a second end of the relay is electrically connected to a first end of the inductor; Wherein, the relay and the thermistor are used to realize the soft start of the totem pole topology converter.

9. A current zero-crossing distortion control method based on a totem pole topology converter. It is characterized in that The totem pole topology converter includes a high-frequency bridge arm switch tube and an industrial frequency bridge arm switch tube; the method includes: Obtaining actual output voltage, rated bus voltage and input current sampling values ​​of the totem pole topology converter; generating an input current reference value based on the actual output voltage and the rated bus voltage; Generate a modulation wave signal based on the input current reference value and the input current sampling value; A high-frequency driving signal for the high-frequency bridge arm switch tube and an industrial frequency driving signal for the industrial frequency bridge arm switch tube are generated based on the modulated wave signal.

10. The current zero-crossing distortion control method according to claim 9, It is characterized in that The step of generating an input current reference value based on the actual output voltage and the rated bus voltage comprises: The actual output voltage is compared with the rated bus voltage to obtain a voltage error; the voltage error, the absolute value of the input voltage of the totem pole topology converter and the reciprocal of the square of the root mean square value of the input voltage are sent to a first proportional integral controller to obtain the input current reference value; The generating of the modulation wave signal based on the input current reference value and the input current sampling value comprises: The input current reference value is compared with the input current sampling value to obtain a current error signal; and the current error signal is sent to a proportional resonant controller or a second proportional integral controller to obtain the modulated wave signal.

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