CN115800796A - Inverter device - Google Patents
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Abstract
The invention provides an inverter device, which belongs to the technical field of inverter design and comprises the following components: the inverter circuit is used for converting the direct current into square wave alternating current; the filter circuit is used for filtering square wave signals with frequency higher than a set frequency in the square wave alternating current so as to obtain feedback signals; the input end of the logic control circuit is connected with the filter circuit, and the output end of the logic control circuit is connected with the inverter circuit; the logic control circuit receives a feedback signal of the filter circuit, calculates a switching angle value by adopting a Specific Harmonic Elimination Pulse Width Modulation (SHEPWM) method according to the feedback signal, generates a Sinusoidal Pulse Width Modulation (SPWM) signal according to the switching angle value, outputs the Sinusoidal Pulse Width Modulation (SPWM) signal to the inverter circuit, and filters harmonic waves corresponding to the switching angle in the square wave alternating current. According to the invention, a SHEPWM technology is added in a control link, and a switching angle value is calculated through a feedback signal of an output circuit to eliminate low-frequency subharmonics with higher amplitude, so that the normal, safe and reliable work of the whole power supply system is ensured.
Description
Technical Field
The invention belongs to the technical field of inverter design, and particularly relates to an inverter device.
Background
With the development of new energy industry, medium and small power inverters are widely applied in electric energy form conversion occasions, such as various fields of microwave communication, field activities, expressways, islands, military affairs, medical treatment, aerospace, new energy power supply and the like. The inverter device plays an important role as a device for converting direct current into alternating current, particularly in the fields of microgrid energy transmission, photovoltaics, energy storage, and the like. With the development of economic society and the increase of user demands, the capacity demand of using an inverter in a microgrid is larger and larger. And high power systems are selectable by two methods: the single power inverter or the low-power inverter is adopted to operate in parallel. The high-power switch device has the problems of high cost, large volume and weight, poor reliability and the like. Therefore, medium and small power inverters are mostly adopted in parallel in engineering to realize high-power application.
The inverter is used as a power electronic device with a main circuit structure and has the characteristics of high efficiency and energy saving. However, in the use process of the inverter device, the nonlinear load is likely to cause the output voltage waveform of the inverter device to be periodically distorted, and the harmonic waves are increased, so that the waveform loaded on the load is distorted, and a large amount of harmonic waves in the operation process bring great harm to a power grid, electric equipment, a communication network and the like.
With the increase of the switching frequency of the inverter, the power electronic converter with the switching frequency of tens to hundreds of KHz is used as a main source of higher harmonics, which can cause the adverse effects of intermittent operation or functional failure of equipment. Such as: the power carrier brings adverse effects to other power frequency equipment, specifically voltage waveform distortion caused by a carrier signal finally causes misoperation of the terminal equipment; the voltage signal causes overheating or other interference of equipment through terminal equipment, so that the normal, safe and reliable work of the whole power supply system is influenced.
Therefore, it is desirable to optimize the inverter by combining effective harmonic cancellation techniques.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides an inverter.
In order to achieve the above purpose, the invention provides the following technical scheme:
an inverter device comprising:
the inverter circuit is used for converting the input direct current into square wave alternating current;
the input end of the filter circuit is connected with the output end of the inverter circuit and is used for filtering square wave signals with frequency higher than a set frequency in the square wave alternating current so as to obtain feedback signals;
the input end of the logic control circuit is connected with the filter circuit, and the output end of the logic control circuit is connected with the inverter circuit;
the logic control circuit receives a feedback signal of the filter circuit, calculates a switch angle value according to the feedback signal by adopting a Specific Harmonic Elimination Pulse Width Modulation (SHEPWM) method, generates a Sinusoidal Pulse Width Modulation (SPWM) signal through the switch angle value, and outputs the Sinusoidal Pulse Width Modulation (SPWM) signal to the inverter circuit.
Preferably, the feedback signal comprises a current transient and a voltage transient, and the logic control circuit comprises a Sinusoidal Pulse Width Modulation (SPWM) controller and a feedback loop; the input end of the feedback loop is connected with the signal feedback end of the filter circuit, the output end of the feedback loop is connected with the signal input end of the Sinusoidal Pulse Width Modulation (SPWM) controller, and the signal output end of the Sinusoidal Pulse Width Modulation (SPWM) controller is connected with the inverter circuit;
the feedback loop receives the current instantaneous value and the voltage instantaneous value fed back by the filter circuit and sends the current instantaneous value and the voltage instantaneous value to the Sinusoidal Pulse Width Modulation (SPWM) controller;
the sinusoidal pulse width modulation SPWM controller calculates a switching angle value according to a received current instantaneous value and a received voltage instantaneous value and by adopting a specific harmonic elimination pulse width modulation method SHEPWM, generates a sinusoidal pulse width modulation SPWM signal through the switching angle value, outputs the sinusoidal pulse width modulation SPWM signal to a switch of the inverter circuit, controls the on-off of the switch of the inverter circuit, and filters harmonics corresponding to a switching angle in square-wave alternating current.
Preferably, the sinusoidal pulse width modulation SPWM controller outputs a sinusoidal wave by pulse width modulation with a triangular wave as a carrier.
Preferably, the specific process of the sinusoidal pulse width modulation SPWM controller logic control circuit generating the sinusoidal pulse width modulation SPWM signal is:
determining the number of switching angles and a modulation degree interval;
according to the number of the switching angles and the modulation degree interval, solving the switching angles corresponding to the corresponding modulation degrees by adopting a Newton iterative algorithm;
selecting a modulation degree to determine a corresponding switch angle, and obtaining a relationship between the switch angle and the modulation degree through interpolation calculation to obtain a switch curve;
storing the off-line parameters of the switch curve, and storing polynomial coefficients corresponding to the curve to form a lookup table for reference;
acquiring a corresponding modulation degree according to a current instantaneous value and a voltage instantaneous value fed back by a filter circuit acquired actually, and acquiring a switching angle value corresponding to the current instantaneous value and the voltage instantaneous value according to a modulation degree look-up table;
and generating a Sinusoidal Pulse Width Modulation (SPWM) signal according to the switching angle value and the control rule of the three-phase inverter.
Preferably, the inverter circuit comprises a boost inverter circuit, an oscillator circuit and a coil, the boost inverter circuit is used for boosting the input low-voltage direct current into high-voltage direct current by adopting a push-pull architecture, and the oscillator circuit is used for converting the high-voltage direct current into irregular alternating current; the coil is boosted to change irregular alternating current into square wave alternating current.
Preferably, the filter circuit is an alternating current filter circuit composed of a filter capacitor and a filter inductor.
Preferably, some number of harmonics corresponding to the switching anglea n The calculation formula of (2) is as follows:
in the formula (I), the compound is shown in the specification,
is composed of
The ith switching angle of the N switching angles in the interval,Eis constant and n is the harmonic order.
Preference is given toGround, the cut-off frequency of the inverter isw c ：
In the formula (I), the compound is shown in the specification,Las the value of the inductance,Cis a capacitance value.
Preferably, the power supply further comprises an input circuit, an output circuit and an auxiliary loop, wherein the input circuit is connected with the inverter circuit and is used for inputting a direct-current power supply to the inverter circuit; the input end of the output circuit is connected with the output end of the filter circuit and used for supplying power to a load; the auxiliary loop is connected with the input circuit and used for realizing reverse connection protection.
The inverter provided by the invention has the following beneficial effects:
under the condition that the hardware structure is not changed, a specific harmonic elimination SHEPWM technology is added in a control link, low-frequency subharmonics with higher amplitude values are eliminated by calculating a switching angle value through a feedback signal of an output circuit, and the remaining high-frequency subharmonics with lower amplitude values can be eliminated through a filter, so that the adverse effects of intermittent work or functional failure of equipment and the like caused by higher harmonics caused by high switching frequency are avoided, and the normal, safe and reliable work of the whole power supply system is ensured.
Drawings
In order to more clearly illustrate the embodiments of the present invention and the design thereof, the drawings required for the embodiments will be briefly described below. The drawings in the following description are only some embodiments of the invention and it will be clear to a person skilled in the art that other drawings can be derived from them without inventive effort.
Fig. 1 is a hardware configuration diagram of an inverter according to the present invention;
FIG. 2 is a unipolar voltage output waveform;
FIG. 3 is a bipolar voltage output waveform;
FIG. 4 is a SHEPWM-based switching angle simulation result;
FIG. 5 is a diagram of a half-bridge inverter topology;
FIG. 6 is a diagram of a full bridge inverter topology;
FIG. 7 is a three-phase inverter topology block diagram;
FIG. 8 is a flowchart of a SHEPWM method implementation.
Detailed Description
In order that those skilled in the art will better understand the technical solutions of the present invention and can practice the same, the present invention will be described in detail with reference to the accompanying drawings and specific examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing technical solutions of the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that, unless explicitly stated or limited otherwise, the terms "connected" and "connected" are to be interpreted broadly, e.g., as a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate medium. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations. In the description of the present invention, unless otherwise specified, "a plurality" means two or more, and will not be described in detail herein.
Example 1
In order to overcome the disadvantages of the prior art, the present invention provides an inverter, and more particularly, to a compact and small inverter based on a specific harmonic cancellation technique, which can achieve the elimination of higher harmonics (non-even harmonics and integral multiple harmonics of 3), thereby reducing the size and increasing the frequency while obtaining good performance.
In the embodiment, a Specific Harmonic Elimination Pulse Width Modulation (SHEPWM) method is adopted to eliminate the high-order Harmonic in the circuit, and the switching time is optimally selected to generate a Sinusoidal Pulse Modulation Signal (SPWM) to eliminate the specific low-order Harmonic, so that the method has the advantages of high direct-current voltage utilization rate and small direct-current side filter size.
Specifically, as shown in fig. 1, the inverter device provided in this embodiment includes an input circuit, an inverter circuit, an auxiliary circuit, a logic control circuit, a filter circuit, and an output circuit. The input circuit is used for inputting a direct-current power supply; the input end of the inverter circuit is connected with the input circuit and is used for converting the direct current into square wave alternating current; the input end of the filter circuit is connected with the output end of the inverter circuit and is used for filtering square wave signals which do not meet the frequency requirement in the square wave alternating current so as to obtain feedback signals; wherein the feedback signal includes a current transient and a voltage transient. The input end of the output circuit is connected with the output end of the filter circuit and used for supplying power to a load; the input end of the logic control circuit is connected with the signal feedback end of the filter circuit, the output end of the logic control circuit is connected with the inverter circuit, and the input circuit supplies power for the logic control circuit.
The logic control circuit receives a feedback signal of the filter circuit, calculates a switch angle value by adopting a Specific Harmonic Elimination Pulse Width Modulation (SHEPWM) method according to the feedback signal, generates a Sinusoidal Pulse Width Modulation (SPWM) signal through the switch angle value, outputs the Sinusoidal Pulse Width Modulation (SPWM) signal to the inverter circuit, and filters specific subharmonics corresponding to a switch angle in the square wave alternating current.
The inverter circuit comprises a boosting inverter circuit, an oscillation circuit and a coil, the boosting inverter circuit realizes voltage inversion through a single-phase/three-phase full-bridge push-pull circuit, the input low-voltage direct current voltage (usually 12V/24V) is boosted to more than three hundred volts, the input circuit is large, and a push-pull frame is usually adoptedStructuring; the boost output needs to be greater than
Generally, a certain margin is required to be left when the device is stably operated under heavy load. The oscillating circuit converts direct current into alternating current, and the coil boosts the voltage to convert irregular alternating current into square wave alternating current.
The filter circuit is an alternating current filter circuit consisting of a filter capacitor and a filter inductor. The input end of the output circuit is connected with the output end of the filter circuit and used for providing sine wave alternating current for a load and supplying power to the load part.
The auxiliary loop comprises a voltage starting loop, a power supply and a reverse connection prevention protection part and is connected with the input circuit. The auxiliary loop is used as an additional part of the circuit system to realize power supply and reverse connection protection.
In this embodiment, the logic control circuit includes a Sinusoidal Pulse Width Modulation (SPWM) controller and a feedback loop; the input end of the feedback loop is connected with the signal feedback end of the filter circuit, the output end of the feedback loop is connected with the signal input end of the Sinusoidal Pulse Width Modulation (SPWM) controller, and the signal output end of the Sinusoidal Pulse Width Modulation (SPWM) controller is connected with the inverter circuit.
Specifically, the feedback loop receives a current instantaneous value and a voltage instantaneous value fed back by the filter circuit and sends the current instantaneous value and the voltage instantaneous value to the Sinusoidal Pulse Width Modulation (SPWM) controller; the Sinusoidal Pulse Width Modulation (SPWM) controller calculates a switching angle value by adopting a Specific Harmonic Elimination Pulse Width Modulation (SHEPWM) method according to a received current instantaneous value and a received voltage instantaneous value, generates 4 paths of Sinusoidal Pulse Width Modulation (SPWM) signals sharing the ground through the switching angle value, outputs the Sinusoidal Pulse Width Modulation (SPWM) signals to a switch of an inverter circuit, controls the on-off of an MOS (metal oxide semiconductor) switching tube of the switch of the inverter circuit, filters specific subharmonics in square wave alternating current, and calculates 10-order harmonic analysis. The Sinusoidal Pulse Width Modulation (SPWM) controller takes triangular waves as carriers (unipolar and bipolar), and outputs sinusoidal waves through pulse width modulation.
In specific application, the key point of the sinusoidal pulse width modulation SPWM controller lies in the selection of an initial value, and iterative non-local convergence and rapidity of operation need to be ensured, so that a switching angle is obtained.
The working principle of the specific harmonic elimination pulse width modulation SHEPWM method is introduced by taking a single/bipolar three-phase voltage type inverter as a research object.
Firstly, taking a single-phase voltage type inverter as an example, a mathematical model of a specific harmonic elimination technology is established.
As shown in fig. 8, a mathematical model is established based on the waveform of the output voltage of the single-phase voltage source inverter, so that the unipolar voltage waveforms of the inverter are respectively shown in fig. 2, taking 1/4 period as an example. And the voltage values are displayed after being converted according to the proportion distribution.
The inverter bipolar voltage waveforms are shown in fig. 3, and each single cycle is taken as an example.
Omega is the frequency of the wave to be measured,tsin is a sine function, cos is a pre-function,a n 、b n are the coefficients of the fourier expansion.
In FIG. 4, the voltage waveform at which f (ω t) can be obtained is an odd function, i.e., f (ω t) is at [0, π]In intervals of
Is axisymmetric at [0,2 π]The interval is symmetrical by pi points, namely:
therefore, when the coefficients of expressions of direct current component, cosine component and even component after Fourier series decomposition are obtained are 0, the Fourier decomposition coefficients can be simplified as follows:
and odd order sinusoidal components:
in the formula (I), the compound is shown in the specification,
is composed of
The ith switching angle of the N switching angles in the interval,Eis constant and n is the harmonic order. The idea behind SHEPWM is to make the switching angle a few harmonics
(identity equal to 0) to achieve cancellation of specific harmonics.
For a three-phase inverter, because of the three-phase symmetry of the load, the multiple harmonic of 3 in the output voltage is eliminated, so that only the multiple harmonic of 3 is needed to be eliminated, and the formula (8) can be simplified as follows:
the above expression is in
The interval has N switching angles, and the modulation ratio is defined as:
namely the ratio of the fundamental wave secondary value of the inverter output phase voltage to the inverter direct current bus voltage ranges from 0 to 1.15. Wherein
，（12）
The corresponding switching angle needs to be satisfied. Thus, the system of equations is formed
N switching angles are used to eliminate N-1 expressions of specific harmonic orders within a cycle. On the other hand, a mathematical model is established for the waveform of the phase A of the output voltage of the three-phase voltage type inverter, and the output voltage waveforms of the phase B and the phase C only need to be shifted by 120 degrees and 240 degrees. According to the sinusoidal pulse width modulation SPWM controller, a switching angle simulation result shown in FIG. 4 is obtained by applying seven switching angles, which are taken as an example, of a three-phase voltage type inverter. For a three-phase symmetric system, integral multiple harmonics of three are automatically eliminated because of the same phase, so that the output switch angle corresponding to the non-three integral multiple odd number corresponds to seven switch angles, namely a in the simulation result 1 ,a 2 ,a 3 ,a 4 ,a 5 ,a 6 ,a 7 。
Wherein in the inverter setting process, the cut-off frequency is:
namely, after the specific harmonic elimination (SHEPWM method), the cut-off frequency can be greatly improved, and meanwhile, the L and C types are reduced, so that the size of the inverter is reduced, and the cost is reduced.
Therefore, during the design process of the inversion equipment with the same parameters, a specific subharmonic elimination method by introducing SHEPWM (short pulse width modulation), namely
The cutoff frequency is inversely proportional to the square root of the LC product. Can be increased byThe frequency is cut off, so that the numerical values of L and C are greatly reduced, and the aim of reducing the design volume is fulfilled.
Inverters are classified by thyristor connection and can be classified into series inverters, parallel inverters, and bridge inverters. The description of the hardware topology of the bridge inverter can be divided into: the topology structure of half-bridge inversion, full-bridge inversion and three-level inversion is shown in fig. 5 to 7. In the aspect of specific hardware design, on the basis of an LC filter circuit, the inverter frequency can be increased without adding more hardware modules.
On the basis of an SPWM control framework, a specific harmonic elimination-based SHEPWM method is adopted in a control link, and the high-frequency and small-volume design of the inverter is realized through the improvement of the optimization method on the design mode.
The operating principle of the inverter provided by the invention is as follows:
the input current is converted into smooth direct current through an input circuit, and the direct current is transmitted to an inverter circuit through the input circuit.
In a logic control circuit generated by PWM, the current inner loop and the voltage outer loop are controlled comprehensively through feedback information of a filter circuit, a specific harmonic elimination pulse width modulation method SHEPWM is integrated, and finally SPWM waveforms are generated to an inverter circuit part and then are output to a load through the filter circuit and an output circuit.
In addition, the auxiliary protection circuit supplies power to small signal parts (such as a PWM signal chip, an operational amplifier power supply, a single chip microcomputer and the like).
The inverter circuit completes the inversion function through the connection and disconnection of the power electronic switch, and converts direct current into required alternating current. The on-off of the power electronic switching device needs to be controlled by a certain driving pulse, and a circuit for generating and adjusting the pulse becomes a logic control circuit.
The specific control process of the sinusoidal pulse width modulation SPWM controller is as follows:
step 7, acquiring a corresponding modulation degree according to the actually acquired target output current and voltage of the three-phase inverter (the actually acquired current instantaneous value and voltage instantaneous value fed back by the filter circuit), and acquiring a switch angle value corresponding to the current instantaneous value and the voltage instantaneous value according to a modulation degree table;
step 8, generating an SPWM signal according to the switching angle and the control law of the three-phase inverter;
and 9, after the selection of the switching angle is finished, outputting the SPWM waveform to the inverter circuit according to the angles to realize the elimination of the specific harmonic wave.
In the specific calculation process of step 5, the calculation is developed according to the formulas (6) to (8), wherein:
N=7,
the invention adopts a specific harmonic elimination SHEPWM technology, provides great advantages for reducing the design volume in the design process of medium and small power inverters, and can meet the application of more limited spaces. The specific harmonic elimination pulse width modulation method SHEPWM eliminates the selected low-order harmonic through the optimized selection of the switching time, and has the following obvious advantages:
under the condition that the hardware structure is not changed, the specific harmonic elimination SHEPWM technology is added in the control link, and the size and the cost of the inverter design can be greatly reduced.
At the same switching frequency, an optimal output voltage waveform can be generated, thereby reducing current ripples and torque pulses of the motor, and improving control performance as a whole.
The invention combines a specific harmonic elimination pulse width modulation method SHEPWM, reduces direct current side current ripples by improving waveform quality, filters specific subharmonics, increases designed maximum cut-off frequency, and can solve the problems of overlarge power supply size, high cost and complex circuit. Meanwhile, the size of the direct current side filter is reduced, and the advantage of size reduction of the inverter is achieved.
Under the condition of the same waveform quality, the lowest switching frequency can be obtained by using a specific harmonic elimination pulse width modulation method SHEPWM, so that the switching loss is effectively reduced, the conversion efficiency is improved, the higher fundamental voltage can be obtained by modulating high-voltage high-power equipment, and the utilization rate of direct-current voltage is improved. The simple and superior inverter design effect is realized by utilizing the switching angular frequency of the cubic polynomial fitting system.
The device can be used with a generator in a matching way, so that the effects of saving fuel and reducing noise are achieved; meanwhile, the medium and small-sized inverter can be applied to automobiles, steamships and portable power supply equipment.
The above-mentioned embodiments are only preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and any simple modifications or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.
Claims (9)
1. An inverter device, comprising:
the inverter circuit is used for converting the input direct current into square wave alternating current;
the input end of the filter circuit is connected with the output end of the inverter circuit and is used for filtering square wave signals with frequency higher than a set frequency in the square wave alternating current so as to obtain feedback signals;
the input end of the logic control circuit is connected with the filter circuit, and the output end of the logic control circuit is connected with the inverter circuit;
the logic control circuit receives a feedback signal of the filter circuit, calculates a switch angle value according to the feedback signal by adopting a Specific Harmonic Elimination Pulse Width Modulation (SHEPWM) method, generates a Sinusoidal Pulse Width Modulation (SPWM) signal through the switch angle value, and outputs the Sinusoidal Pulse Width Modulation (SPWM) signal to the inverter circuit.
2. The inverter apparatus according to claim 1, wherein the feedback signals are a current transient and a voltage transient, and the logic control circuit comprises a Sinusoidal Pulse Width Modulation (SPWM) controller and a feedback loop; the input end of the feedback loop is connected with the signal feedback end of the filter circuit, the output end of the feedback loop is connected with the signal input end of the Sinusoidal Pulse Width Modulation (SPWM) controller, and the signal output end of the Sinusoidal Pulse Width Modulation (SPWM) controller is connected with the inverter circuit;
the feedback loop receives the current instantaneous value and the voltage instantaneous value fed back by the filter circuit and sends the current instantaneous value and the voltage instantaneous value to the Sinusoidal Pulse Width Modulation (SPWM) controller;
the sinusoidal pulse width modulation SPWM controller calculates a switching angle value according to a received current instantaneous value and a received voltage instantaneous value and by adopting a specific harmonic elimination pulse width modulation method SHEPWM, generates a sinusoidal pulse width modulation SPWM signal through the switching angle value, outputs the sinusoidal pulse width modulation SPWM signal to a switch of the inverter circuit, and controls the on-off of the switch of the inverter circuit.
3. The inverter of claim 2, wherein the Sinusoidal Pulse Width Modulation (SPWM) controller outputs a sine wave by pulse width modulation using a triangular wave as a carrier.
4. The inverter of claim 2, wherein the logic control circuit generates the sinusoidal pulse width modulated SPWM signal by:
determining the number of switching angles and a modulation degree interval;
according to the number of the switching angles and the modulation degree interval, solving the switching angles corresponding to the corresponding modulation degrees by adopting a Newton iterative algorithm;
selecting a modulation degree to determine a corresponding switch angle, and obtaining a relationship between the switch angle and the modulation degree through interpolation calculation to obtain a switch curve;
storing the off-line parameters of the switch curve, and storing polynomial coefficients corresponding to the curve to form a lookup table for reference;
acquiring a corresponding modulation degree according to a current instantaneous value and a voltage instantaneous value fed back by a filter circuit acquired actually, and acquiring a switch angle value corresponding to the current instantaneous value and the voltage instantaneous value according to a modulation degree look-up table;
and generating a Sinusoidal Pulse Width Modulation (SPWM) signal according to the switching angle value and the control rule of the three-phase inverter.
5. The inverter device according to claim 1, wherein the inverter circuit includes a boost inverter circuit for boosting an input low-voltage direct current into a high-voltage direct current in a push-pull architecture, an oscillator circuit for converting the high-voltage direct current into an irregular alternating current, and a coil; the coil is boosted to change irregular alternating current into square wave alternating current.
6. The inverter of claim 1, wherein the filter circuit is an ac filter circuit consisting of a filter capacitor and a filter inductor.
7. The inverter of claim 4, wherein the switching angle corresponds to a number of harmonicsa n The calculation formula of (2) is as follows:
in the formula (I), the compound is shown in the specification,
is composed of
N switching angles within the interval
The angle of each switch is set to be,Eis a constant number of times, and is,
the harmonic order.
8. The inverter device according to claim 1, wherein the inverter device has a cutoff frequency ofw c ：
In the formula (I), the compound is shown in the specification,Las the value of the inductance,Cis a capacitance value.
9. The inverter device according to claim 1, further comprising an input circuit, an output circuit and an auxiliary loop, wherein the input circuit is connected to the inverter circuit and is configured to input a dc power to the inverter circuit; the input end of the output circuit is connected with the output end of the filter circuit and used for supplying power to a load; the auxiliary loop is connected with the input circuit and used for realizing reverse connection protection.
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| CN202310054549.8A CN115800796A (en) | 2023-02-03 | 2023-02-03 | Inverter device |
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| CN202310054549.8A CN115800796A (en) | 2023-02-03 | 2023-02-03 | Inverter device |
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| CN201118459Y (en) * | 2007-10-30 | 2008-09-17 | 新疆新能源股份有限公司 | High-frequency sine wave reverser |
| CN101599649A (en) * | 2009-04-21 | 2009-12-09 | 合肥工业大学 | The modulation system of SPWM inverter control signal in directly-driving wind power generation system and the system |
| CN102983768A (en) * | 2012-11-14 | 2013-03-20 | 国网智能电网研究院 | Optimization control method based on selective harmonic elimination pulse width modulation (SHEPWM) |
| CN104022667A (en) * | 2014-06-19 | 2014-09-03 | 安徽大学 | SHEPWM method for three-level inverter |
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2023
- 2023-02-03 CN CN202310054549.8A patent/CN115800796A/en active Pending
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201118459Y (en) * | 2007-10-30 | 2008-09-17 | 新疆新能源股份有限公司 | High-frequency sine wave reverser |
| CN101599649A (en) * | 2009-04-21 | 2009-12-09 | 合肥工业大学 | The modulation system of SPWM inverter control signal in directly-driving wind power generation system and the system |
| CN102983768A (en) * | 2012-11-14 | 2013-03-20 | 国网智能电网研究院 | Optimization control method based on selective harmonic elimination pulse width modulation (SHEPWM) |
| CN104022667A (en) * | 2014-06-19 | 2014-09-03 | 安徽大学 | SHEPWM method for three-level inverter |
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