Multi-level DC-AC photon electric energy converter and current conversion modulation method thereof

Abstract

The invention discloses a multi-level DC-AC photon electric energy converter and a current conversion modulation method thereof, and aims to solve the problems of complex topology, multiple switching devices, large size, limited number of output levels, relatively high degree of distortion of an output waveform and the like of a traditional switch inverter. According to the multi-level DC-AC photon electric energy converter and the variable-current modulation method thereof, multi-level photon electric energy conversion from direct current input to alternating current output is achieved through topological structure design and the variable-current modulation method, N levels are output, N represents any positive odd number larger than 1, the number of only needed switching tubes is N-1, and the number of the switching tubes is N-1. Compared with a traditional switching converter, the number of used switching devices is reduced by half or more, and the photon electric energy converter has the advantages of being simple in structure, small in number of switching devices, small in size, wide in application range and good in electrical isolation performance, and meanwhile has the advantages of being low in electromagnetic interference and small in output ripple.

Description

Technical Field

[0001] The present invention relates to the field of electric energy conversion, and in particular to a multi-level DC-AC photon electric energy converter and a current conversion modulation method thereof. Background Art

[0002] With the continuous development of photon-to-electric converters in the field of power electronics, photon-to-electric converters have been able to achieve DC-DC, DC-AC, AC-DC, and AC-AC power conversion, promoting the widespread application of photon-to-electric conversion. Traditional multi-level inverters have a large number of switching devices, large size, high output ripple, complex control strategies, and electromagnetic interference problems, making it difficult to meet the needs of high-quality output, especially in precision equipment and high-reliability systems.

[0003] The present invention discloses a DC-AC multi-level photon power converter and a current conversion modulation method thereof, which realizes the energy conversion between DC input and AC output by combining the characteristics of photoelectric materials and the electrical output requirements. Through the flexible configuration of the number of components in the photovoltaic module, a multi-level output form is generated, which addresses the problems of traditional multi-level inverters, a large number of switch devices, a large volume, a limited output level, voltage distortion and electromagnetic interference. While realizing multi-level output, the photon power converter has the advantages of a small number of switch tubes, a small volume, a simple control strategy, low output ripple and low electromagnetic interference, and is particularly suitable for medical equipment with high requirements for power quality, modern communication technology and other fields. Summary of the invention

[0004] The present invention discloses a multi-level DC-AC photon electric energy converter and a current conversion modulation method thereof. The unique characteristics and electrical output characteristics of photoelectric materials are utilized to enable the converter to adjust the number of output levels according to different numbers of photovoltaic elements. The converter uses only N-1 switching devices to achieve N-level output. Compared with the traditional multi-level inverter, the multi-level inverter has a simple circuit structure, a small number of switching devices, a small volume, a simple control strategy, and good electrical isolation. At the same time, it has the advantages of low electromagnetic interference and small output ripple, which expands the application field of the photon electric energy converter and provides a new method for multi-level DC-AC photon electric energy conversion.

[0005] A multi-level DC-AC photon power converter, comprising: an input side DC power supply U DC , input side LED-A, LED-B, LED-C light sources, output side photovoltaic elements PV-A group, PV-B group, control module, output load Z;

[0006] In the following, N is the number of output levels, and N represents any positive odd number greater than 1;

[0007] The control module includes: a switch tube S 1 , S2 ,…S 2n , PWM 1, PWM 2, ..., PWM 2n, and a control unit;

[0008] The output-side photovoltaic element PV-A group: photovoltaic elements PV-A1, PV-A2, ..., PV-An, where n = (N-1) / 2;

[0009] The output side photovoltaic element PV-B group: photovoltaic elements PV-B1, PV-B2, ..., PV-Bn; wherein n = (N-1) / 2;

[0010] The DC power supply U DC The positive electrode is connected to the positive electrodes of the input side LEDA, LED-B, and LED-C light sources;

[0011] The DC power supply U DC The cathode of is connected to the cathode of the input side LEDA, LED-B, and LED-C light sources;

[0012] The output-side photovoltaic elements PV-A1, ..., PV-An are connected in series in the forward direction;

[0013] The output-side photovoltaic elements PV-B1, ..., PV-Bn are connected in series in the forward direction;

[0014] The positive electrode of the output-side photovoltaic element PV-A1 and the negative electrode of PV-B1 are connected to the positive electrode of the output load Z;

[0015] Optionally, the switch device is a fully-controlled switch element, and its switch device ports include: a first port, a second port, and a gate (ie, a signal input port).

[0016] The negative electrodes of the output-side photovoltaic elements PV-A1, ..., PV-An are connected to the switch tube S 1 ,…,S n The first port is connected;

[0017] The positive electrodes of the output-side photovoltaic elements PV-B1, ..., PV-Bn are connected to the switch tubes S n+1 ,…,S 2n The first port is connected;

[0018] The positive electrode of the output load Z is connected to the positive electrode of PV-A1 and the negative electrode of PV-B1;

[0019] The negative pole of the output load Z is connected to S 1 ,…,S 2n The second port is connected;

[0020] Preferably, the emission wavelength of the input-side LEDA, LEDB, LEDC light sources matches the receiving wavelength of the output-side photovoltaic elements PVA group and PVB group, which is beneficial to improving the transmission efficiency of photon energy;

[0021] The output ports of PWM 1, ... PWM 2n are respectively connected to S 1 ,…,S 2n The gate connection;

[0022] A current conversion modulation method for a multi-level DC-AC photon power converter comprises the following steps:

[0023] S1: The control unit outputs a modulation signal to PWM 1, PWM 2, ..., PWM n respectively to S 1 , S 2 ,…,S n The conduction timing of the switch device S 1 , S 2 ,…,S n ,…,S 2 , S 1 Turn on in sequence (only one switch device is turned on in each state) to achieve positive level output;

[0024] S2: The control unit outputs modulation signals to the PWM n+1, PWM n+2, ..., PWM 2n respectively. n+1 , S n+2 ,…,S 2n The switching timing is controlled, the switching device S n+1 , S n+2 ,…,S 2n ,…,S n+2 , S n+1 Turn on in sequence (only one switch device is turned on in each state) to achieve negative level output;

[0025] It can be seen from the above technical methods that the implementation of the case of the present invention has the following beneficial effects:

[0026] The present invention discloses a multi-level DC-AC photon power converter and a current conversion modulation method thereof, which uses N-1 switching devices to realize DC input and AC N-level output, and controls the number of output PV photovoltaic elements by controlling the conduction timing of the switching devices, thereby realizing multi-level output, and is applied to DC-AC conversion occasions. The multi-level DC-AC photon power converter uses photons as the energy transmission medium, and compared with the traditional switching converter, it has the advantages of simple structure, fewer switching devices, small size, simple control strategy, low electromagnetic interference, etc., which expands the application field of the photon power converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the prior art and the drawings required for use in the embodiments. The following drawings are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A schematic diagram of a topological structure of a nine-level DC-AC photon power converter in an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the nine-level principle and output waveform of a nine-level DC-AC photon power converter in the positive and negative half cycles in an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of the working state of a switch device in a single cycle of a nine-level DC-AC photon power converter in an embodiment of the present invention;

[0031] Figure 4 1 is an input and output waveform diagram of a nine-level DC-AC photon power converter in an embodiment of the present invention;

[0032] Figure 5 A schematic diagram of the topological structure of an N-level DC-AC photon power converter of the present invention;

[0033] Figure 6 It is a schematic diagram of the multi-level principle and waveform of the positive and negative half-cycle output of an N-level DC-AC photon power converter of the present invention;

[0034] Figure 7 It is a schematic diagram of the working state of a switch device in a single cycle of an N-level DC-AC photon power converter of the present invention;

[0035] Figure 8 An input and output waveform diagram of an N-level DC-AC photon power converter of the present invention; DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and features in the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments that can be obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] Specifically, the multi-level DC-AC photonic power converter provided in the present invention can output multiple levels. In practical applications, users can select the number of photovoltaic elements in the photovoltaic module according to actual needs to obtain multiple levels. In this application, nine-level output is taken as an example, namely, photovoltaic element PV-A group and photovoltaic element PV-B group, each containing 4 photovoltaic elements.

[0038] Please refer to Figure 1 , Figure 1 The topological structure of a nine-level DC-AC photon power converter of the present invention includes: an input side DC power supply U DC , input side LED-A, LED-B light source, output side photovoltaic element PV-A group, PV-B group, control module, output load Z, its output voltage U O (t) output nine levels;

[0039] The output side photovoltaic element PV-A group: photovoltaic elements PV-A1, PV-A2, PV-A3, PV-A4;

[0040] The output side photovoltaic element PV-B group: photovoltaic elements PV-B1, PV-B2, PV-B3, PV-B4;

[0041] The DC power supply U DC The positive electrode is connected to the positive electrode of the input side LEDA and the positive electrode of the input side LEDB;

[0042] The DC power supply U DC The cathode of is connected to the cathode of the input side LEDA and the cathode of the input side LEDB;

[0043] The output-side photovoltaic elements PV-A1, PV-A2, PV-A3, and PV-A4 are connected in series in the forward direction;

[0044] The output-side photovoltaic elements PV-B1, PV-B2, PV-B3, and PV-B4 are connected in series in the forward direction;

[0045] The positive electrode of the output-side photovoltaic element PV-A1 and the negative electrode of PV-B1 are connected to the positive electrode of the output load Z;

[0046] The control module includes: a switch device S 1 ,…,Switching device S 8 , PWM 1, PWM 2, ..., PWM 8 and a control unit;

[0047] Optionally, the switch device is a fully-controlled switch element, and the switch device ports include: a first port, a second port, and a gate (signal input port).

[0048] The negative electrodes of the output-side photovoltaic elements PV-A1, ..., PV-A4 are respectively connected to the switching devices S 1 ,…,S 4 The first port is connected;

[0049] The positive electrodes of the output-side photovoltaic elements PV-B1, ..., PV-B4 are respectively connected to the switch devices S 5 ,…,S 8 The first port is connected;

[0050] The control unit is connected to the input ports of PWM 1, ...PWM 8 respectively;

[0051] The output ports of the PWM 1, ... PWM 8 are respectively connected to the switching devices S 1 ,…,S 8 The gate connection;

[0052] The positive electrode of the output load Z is connected to the positive electrode of the photovoltaic element PV-A1 and the negative electrode of PV-B1;

[0053] The negative electrode of the output load Z is connected to the switching device S 1 ,…,S 8 The second port is connected;

[0054] Please refer to Figure 2 , a modulation method principle and output waveform diagram of a nine-level photon-to-electricity converter, wherein the modulation method is:

[0055] S1: The control unit outputs a modulation signal to PWM 1, PWM 2, ..., PWM4 respectively to S 1 , S 2 ,…,S 4 The switching timing is controlled, the switching device S 1 , S 2 , S 3 , S 4 , S 3 , S 2 , S 1 Turn on in sequence (only one switch device is turned on in each state) to achieve positive level output;

[0056] S2: The control unit outputs a modulation signal to the PWM 5, PWM 6, ..., PWM 8 respectively. 5 , S 6 , S 7 , S 8 The switching timing is controlled, the switching device S 5 , S 6 , S 7 , S 8, S 7 , S 6 , S 5 Turn on in sequence (only one switch device is turned on in each state) to achieve negative level output;

[0057] Please refer to Figure 3 , Figure 3 The working state diagram of each switching device in a single cycle, the specific conduction sequence is as follows:

[0058] The modulation method to achieve positive half-cycle output, the specific conduction sequence is as follows:

[0059] T 1 :S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 7 , S 8 Shut down;

[0060] T 2 :S 1 On, S 2 , S 3 , S 4 , S 5 , S 6 , S 7 , S 8 Shut down;

[0061] T 3 :S 2 On, S 1 , S 3 , S 4 , S 5 , S 6 , S 7 , S 8 Shut down;

[0062] T 4 :S 3 On, S 1 , S 2 , S 4 , S 5 , S 6 , S 7 , S 8 Shut down;

[0063] T 5 :S 4 On, S 1 , S 2 , S 3 , S 5 , S 6 , S7 , S 8 Shut down;

[0064] T 6 :S 3 On, S 1 , S 2 , S 4 , S 5 , S 6 , S 7 , S 8 Shut down;

[0065] T 7 :S 2 On, S 1 , S 3 , S 4 , S 5 , S 6 , S 7 , S 8 Shut down;

[0066] T 8 :S 1 On, S 2 , S 3 , S 4 , S 5 , S 6 , S 7 , S 8 Shut down;

[0067] Positive half cycle output voltage U O1 (t) is:

[0068]

[0069] Time T for appealing each status x for:

[0070]

[0071] Where T is a single cycle time, N is the number of levels;

[0072] The modulation method to achieve negative half-cycle output, the specific conduction sequence is as follows:

[0073] T 9 :S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 7 , S 8 Shut down;

[0074] T 10 :S5 On, S 1 , S 2 , S 3 , S 4 , S 6 , S 7 , S 8 Shut down;

[0075] T 11 :S 6 On, S 1 , S 2 , S 3 , S 4 , S 5 , S 7 , S 8 Shut down;

[0076] T 12 :S 7 On, S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 8 Shut down;

[0077] T 13 :S 8 On, S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 7 Shut down;

[0078] T 14 :S 7 On, S 1 , S 2 , S 3 , S 4 , S 5 , S 6 , S 8 Shut down;

[0079] T 15 :S 6 On, S 1 , S 2 , S 3 , S 4 , S 5 , S 7 , S 8 Shut down;

[0080] T 16 :S 5On, S 1 , S 2 , S 3 , S 4 , S 6 , S 7 , S 8 Shut down;

[0081] Negative half cycle output voltage U O2 (t) is:

[0082]

[0083] Time T for appealing each status X for:

[0084]

[0085] Where T is a single cycle time, N is the number of levels;

[0086] Please refer to Figure 4 , Figure 4 The input and output voltage waveforms of a nine-level DC-AC photon power converter. The output voltage U O (t) is:

[0087]

[0088] In summary, the present invention discloses a multi-level DC-AC photonic power converter and its current conversion modulation method, combines the properties of optoelectronic materials and electrical output characteristics to achieve DC-AC power conversion of the photonic power converter, uses N-1 switching devices to achieve N-level output, and provides a method for achieving multi-level, which will expand the application field of the photonic power converter.

[0089] The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. The description of the embodiments disclosed in the present invention enables professional and technical personnel in the field to use or implement the present invention. They can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these replacements or modifications do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A multi-level DC-AC photon power converter, characterized in that: include: Input DC power supply U DC , input side LED-A, LED-B, LED-C light sources, output side photovoltaic elements PV-A group, PV-B group, control module, output load Z; In the following, N is the number of output levels, and N represents any positive odd number greater than 1; The control module includes: switch devices S1, S2, ..., switch devices S 2n , PWM1, PWM2, ..., PWM 2n, and a control unit; The output-side photovoltaic element PV-A group: photovoltaic elements PV-A1, PV-A2, ..., PV-An, where n = (N-1) / 2; The output side photovoltaic element PV-B group: photovoltaic elements PV-B1, PV-B2, ..., PV-Bn, where n = (N-1) / 2; The DC power supply U DC The positive electrode is connected to the positive electrodes of the input side LEDA, LED-B, and LED-C light sources; The DC power supply U DC The cathode of is connected to the cathode of the input side LEDA, LED-B, and LED-C light sources; The output-side photovoltaic elements PV-A1, ..., PV-An are connected in series in the forward direction; The output-side photovoltaic elements PV-B1, ..., PV-Bn are connected in series in the forward direction; The positive electrode of the output-side photovoltaic element PV-A1 and the negative electrode of PV-B1 are connected to the positive electrode of the output load Z; Optionally, the switch device is a fully-controlled switch element, and the ports of the switch device include: a first port, a second port, and a gate (ie, a signal input port). The negative electrodes of the output-side photovoltaic elements PV-A1, ..., PV-An are connected to the switching devices S1, ..., S n The first port is connected; The positive electrodes of the output-side photovoltaic elements PV-B1, ..., PV-Bn are respectively connected to the switching devices S n+1 ,…,S 2n The first port is connected; The positive electrode of the output load Z is connected to the positive electrode of PV-A1 and the negative electrode of PV-B1; The negative electrode of the output load Z is connected to the switching devices S1, ..., S 2n The second port is connected; The control unit is connected to the input ports of PWM 1, ...PWM 2n respectively; The output ports of PWM 1, ... PWM 2n are connected to S1, ..., S 2n The gate connection.

2. A current conversion modulation method for a multi-level DC-AC photonic power converter, characterized in that: A multi-level DC-AC photon power converter as described in claim 1 is adopted, and its specific current conversion modulation method is: S1: The control unit outputs a modulation signal to PWM 1, PWM 2, ..., PWMn to respectively control S1, S2, ..., S n The conduction timing of the switch devices S1, S2, ..., S n , ..., S2, S1 are turned on in sequence (only one switch device is turned on in each state) to achieve positive level output; S2: The control unit outputs modulation signals to PWMn+1, PWMn+2, ..., PWM 2n respectively. n+1 , S n+2 ,…,S 2n The switching timing is controlled, the switching device S n+1 , S n+2 ,…,S 2n ,…,S n+2 , S n+1 They are turned on in sequence (only one switch device is turned on in each state) to achieve negative level output.

3. The current conversion modulation method of a multi-level DC-AC photonic power converter according to claim 2, characterized in that: The control unit controls the switching devices S1, S2, ..., S n The PWM modulation of S1 is: The output side photovoltaic element PV-A group works, and the output is a multi-level positive half cycle, wherein the number of multi-levels is determined according to the number of PV photovoltaic elements that are turned on in the output side photovoltaic element PV-A group, and the positive half cycle outputs a multi-level voltage U O1 (t) Formula:

4. According to claim 2, the current conversion modulation method of a multi-level DC-AC photonic power converter is characterized in that: The control unit controls the switching device S n+1 , S n+2 ,…,S 2n The PWM modulation of S2 is: The output side photovoltaic element PV-B group works, and the output is a negative half-cycle multi-level, wherein the number of multi-levels is determined according to the number of photovoltaic elements of the output side photovoltaic element PV-B group that are turned on, and the negative half-cycle output multi-level voltage U O2 (t) Formula:

5. According to claim 3 or 4, a multi-level DC-AC photon power converter has a single cycle complete output voltage U O (t) is: The working hours for each status are: Where T is a single cycle time and N is the number of levels.

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