Single-phase boost type high-frequency energy storage converter and control method

Abstract

The invention belongs to the technical field of electrics, and particularly relates to a single-phase boost type high-frequency energy storage converter and a control method. The positive polarity input end of the energy storage converter is connected with one end of an input filter inductor and the positive pole of an input filter capacitor; the negative polarity input end of the energy storage converter is connected with the negative electrode of the input filter capacitor, the source electrode of the second switch tube, the source electrode of the fourth switch tube and the negative electrode of the direct current bus capacitor; the other end of the input filter inductor is connected with the source electrode of the first switch tube and the drain electrode of the second switch tube; the positive electrode of the direct-current bus capacitor is connected with the drain electrode of the first switch tube and the drain electrode of the third switch tube; the energy storage converter is connected with the output filter circuit, a first port of the output filter circuit is connected with a power grid or load equipment, and a second port of the output filter circuit is connected with a source electrode of the third switch tube, a drain electrode of the fourth switch tube, a source electrode of the first switch tube and a drain electrode of the second switch tube.

Description

Technical Field

[0001] The present invention belongs to the field of electrical technology, and in particular relates to a single-phase boost high-frequency energy storage converter and a control method thereof. Background Art

[0002] The single-phase high-frequency energy storage converter can invert the DC power stored in the battery into single-phase high-frequency (500Hz-1000Hz) AC power to supply power to the high-frequency AC grid, or drive the ultra-high-speed single-phase asynchronous motor. It can also realize the charging of the battery by the high-frequency AC grid, or recover the power generated by the ultra-high-speed single-phase asynchronous motor under the feedback braking state to improve the motor operation efficiency. In order to reduce line current and copper loss and improve operation efficiency, the effective value of the supply voltage of the single-phase high-frequency AC grid and the single-phase asynchronous motor is usually high, about 110V or 220V. However, for safety reasons, the output voltage of the battery generally does not exceed 100V. Therefore, the single-phase high-frequency energy storage converter in the above application scenarios needs to have a certain boost capability. The two-stage boost energy storage converter of the Buck / Boost converter cascade H-bridge inverter has many advantages such as simple structure, convenient control, and high efficiency. It is a common architecture for single-phase boost high-frequency energy storage converters. However, the number of its components is large, the cost is high, and the two-stage structure has an inherent cascade stability problem, and the design of the controller parameters is relatively complex. The split-source single-phase inverter reuses the power tubes of the Boost converter and the H-bridge inverter, realizes the integration of the two, and reduces the number of power tubes. However, in order to prevent short circuits between adjacent bridge arms, two blocking diodes need to be connected in series at the power input end, resulting in energy not being able to flow in both directions, so it is not suitable for energy storage converters. The differential inverter uses two bidirectional Boost converters to connect differentially, achieving boost and inversion at the same time, and energy can flow in both directions. The circuit structure is simple and the number of components is small. However, the inverter has a circulation problem, and the voltage stress and current stress are both high, and the conversion efficiency is low. Summary of the invention

[0003] In view of this, the present invention provides a single-phase boost high-frequency energy storage converter and a control method, which has the advantages of a small number of components, low cost, simple control, no circulating current, and the ability to suppress common-mode current.

[0004] In order to achieve the above objectives, the following scheme is proposed:

[0005] A single-phase boost high-frequency energy storage converter, the energy storage converter comprising an input filter capacitor C in , input filter inductor L in , DC bus capacitor C dc , the first switch tube S1, the second switch tube S2, the third switch tube S3 and the fourth switch tube S4. Input filter inductor Lin One end of the input filter capacitor C in The positive pole is connected to the positive pole of the energy storage converter as the positive input terminal; the input filter inductor L in The other end is connected to the source of the first switch tube S1 and the drain of the second switch tube S2; the input filter capacitor C in The negative electrode of the second switch tube S2, the source of the fourth switch tube S4 and the DC bus capacitor C dc The negative pole of the DC bus capacitor C is connected to the negative pole of the energy storage converter. dc The positive electrode is connected to the drain of the first switch tube S1 and the drain of the third switch tube S3; the energy storage converter is connected to the output filter circuit, the first port of the output filter circuit is connected to the source of the third switch tube S3, the drain of the fourth switch tube S4 and the source of the first switch tube S1, and the drain of the second switch tube S2, and the second port can be connected to a high-frequency AC power grid, an ultra-high-speed asynchronous motor or a load device.

[0006] When the filter circuit is connected to a load device or an ultra-high-speed asynchronous motor, that is, when it works in an off-grid mode, an LC-type output filter circuit is used; when the filter circuit is connected to a high-frequency AC power grid, that is, when it works in grid-connected operation, an L-type output filter circuit is used.

[0007] Preferably, when the second port of the output filter circuit is connected to an ultra-high-speed asynchronous motor or a load device, the control method comprises the following steps:

[0008] The output voltage sampling value u of the energy storage converter o,f With the output voltage reference value u o,ref Compare and get the output voltage error signal u o,e ;

[0009] The output voltage error signal u o,e It is sent to the output voltage controller and passes through the bidirectional limiting link to obtain the output filter inductor current reference value i Lf,ref ;

[0010] The output filter inductor current reference value i Lf,ref and the output filter inductor current sampling value i Lf,f By comparison, the output filter inductor current error signal i Lf,e , sent to the output filter inductor current controller, and after passing through the bidirectional limiting link, a sinusoidal modulation signal u is obtained. rac ;

[0011] The sinusoidal modulation signal u rac With bipolar triangle carrier u c Intersection, generating a driving signal u for the first switch tube S1 gs,S1 and the fourth switch tube S4 driving signal ugs,S4 ; The first switch tube drive signal u gs,S1 Take the inversion and get the driving signal u of the second switch tube S2 gs,S2 and the driving signal u of the third switch tube S3 gs,S3 .

[0012] Preferably, when the second port is connected to a high-frequency AC power grid, the control method of the energy storage converter comprises the following steps:

[0013] The grid voltage sampling value u of the energy storage converter g,f It is sent to the phase-locked device to obtain the grid voltage phase signal θ;

[0014] The grid current amplitude reference value I set by the energy storage converter g,ref , and the unit sinusoidal signal after the grid voltage phase signal θ is synchronized with the phase to obtain the grid current reference value i g,ref =I g,ref *sin(ωt+θ);

[0015] In the formula, ω o is the output voltage angular frequency.

[0016] The grid current sampling value i of the energy storage converter g,f With the grid current reference value i g,ref By comparison, the grid current error signal i is obtained. g,e ;

[0017] The grid current error signal i g,e It is sent to the output current controller and passes through the bidirectional limiting link to obtain the sinusoidal modulation signal u rac ;

[0018] The sinusoidal modulated signal u rac With bipolar triangle carrier u c Intersection, generating a driving signal u for the first switch tube S1 gs,S1 and the driving signal u of the fourth switch tube S4 gs,S4 ; The first switch tube drive signal u gs,S1 Take the inversion and get the driving signal u of the second switch tube S2 gs,S2 and the driving signal S3u of the third switch tube gs,S3 .

[0019] Furthermore, the voltage gain G of the inverter is U om / U in =2M, where M = U rm / U cm =U om / U dc is the modulation ratio of the energy storage converter; where U rmis the sinusoidal modulated signal u rac The amplitude, U cm is the triangular carrier u c The amplitude, U om is the output voltage u of the energy storage converter o The fundamental amplitude, U dc is the DC bus voltage u dc The average value, U in is the input voltage u in The average value of .

[0020] Furthermore, the input filter inductor L in The inductance is as follows:

[0021]

[0022] Where P o is the output active power, ω o is the output voltage angular frequency, M is the modulation ratio of the energy storage converter, U in is the input voltage u in The average value of .

[0023] Compared with the prior art, the present invention has the following technical effects:

[0024] The single-phase boost high-frequency energy storage converter proposed in the present invention realizes the integration of the Boost converter and the H-bridge inverter by reusing the power tubes of the two, thereby reducing the number of power tubes and allowing energy to flow in both directions; power conversion only requires a single-stage structure, and there is no cascade stability problem, the conversion efficiency is high, and it has the advantages of low cost, simple control, no circulating current, and the ability to suppress common-mode current. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 (a) is a schematic diagram of a circuit structure of a single-phase boost high-frequency energy storage converter provided by the present invention operating in an off-grid mode;

[0026] Figure 1 (b) is a schematic diagram of the circuit structure of a single-phase boost high-frequency energy storage converter provided by the present invention working in a grid-connected mode;

[0027] Figure 2 (a) is a control strategy block diagram of a single-phase boost high-frequency energy storage converter provided by the present invention operating in an off-grid mode;

[0028] Figure 2 (b) is a control strategy block diagram of a single-phase boost high-frequency energy storage converter provided by the present invention operating in a grid-connected mode;

[0029] Figure 3A modal analysis diagram of a single-phase boost high-frequency energy storage converter in a positive half-cycle of an industrial frequency provided by the present invention;

[0030] Figure 4 A modal analysis diagram of a single-phase boost high-frequency energy storage converter in a negative half-cycle of the power frequency provided by the present invention;

[0031] Figure 5 (a) is a main waveform diagram of a switching cycle in a positive half cycle of a single-phase boost high-frequency energy storage converter provided by the present invention;

[0032] Figure 5 (b) is a main waveform diagram of a switching cycle in the negative half cycle of the power frequency of a single-phase boost high-frequency energy storage converter provided by the present invention;

[0033] Figure 6 A schematic diagram of a curve showing the relationship between the modulation ratio and the DC gain of a single-phase boost high-frequency energy storage converter provided by the present invention;

[0034] Figure 7 A closed-loop simulation waveform diagram of a single-phase boost high-frequency energy storage converter provided by the present invention when operating in an off-grid mode;

[0035] Figure 8 A closed-loop simulation waveform diagram of a single-phase boost high-frequency energy storage converter provided by the present invention when operating in a grid-connected mode. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] A single-phase boost high-frequency energy storage converter includes an input filter capacitor C in , input filter inductor L in , DC bus capacitor C dc , the first switch tube S1, the second switch tube S2, the third switch tube S3 and the fourth switch tube S4. Input filter inductor L in One end of the input filter capacitor C in The positive electrode is connected to the positive pole of the energy storage converter as the positive input terminal; the input filter inductor L in The other end is connected to the source of the first switch tube S1 and the drain of the second switch tube S2; the input filter capacitor C in The negative electrode of the second switch tube S2, the source of the fourth switch tube S4 and the DC bus capacitor C dcThe negative pole of the DC bus capacitor C is connected to the negative pole of the energy storage converter. dc The positive electrode is connected to the drain of the first switch tube S1 and the drain of the third switch tube S3; the energy storage converter is connected to the output filter circuit, the first port of the output filter circuit is respectively connected to the source of the third switch tube S3, the drain of the fourth switch tube S4 and the source of the first switch tube S1, and the drain of the second switch tube S2, and the second port can be connected to a high-frequency AC power grid, an ultra-high-speed asynchronous motor or a load device.

[0038] like Figure 1 As shown in (a), when the second port of the output filter circuit is connected to the load device and the ultra-high-speed asynchronous motor, that is, when working in the off-grid mode, an LC type output filter circuit is used; Figure 1 As shown in (b), when the second port of the energy storage converter output filter circuit is connected to the high-frequency AC grid, that is, when it works in grid-connected operation, an L-type output filter circuit is used.

[0039] like Figure 2 As shown, the present invention also provides a control method for a single-phase boost high-frequency energy storage converter.

[0040] A control method for a single-phase boost high-frequency energy storage converter, the control method for the energy storage converter includes off-grid operation control and grid-connected operation control. When the energy storage converter works in off-grid mode, the energy storage converter is controlled to provide power to a load device; when the energy storage converter works in grid-connected mode, the energy storage converter is controlled to provide power to a power grid, or the power grid charges the battery of the energy storage converter.

[0041] When the second port of the output filter circuit of the energy storage converter is connected to the load device and the ultra-high-speed asynchronous motor, that is, when it works in the off-grid mode, its control method is as follows: Figure 2 (a), specifically comprising the following steps:

[0042] The output voltage sampling value u of the energy storage converter o,f With the output voltage reference value u o,ref Compare and get the error signal u o,e ;

[0043] The error signal u o,e It is sent to the output voltage controller and passes through the bidirectional limiting link to obtain the output filter inductor current reference value i Lf,ref ;

[0044] The output filter inductor current reference value i Lf,ref and the output filter inductor current sampling value i Lf,f By comparison, the error signal i Lf,e , sent to the output filter inductor current controller, and after passing through the bidirectional limiting link, a sinusoidal modulation signal u is obtained.rac ;

[0045] The sinusoidal modulated signal u rac With bipolar triangle carrier u c Intersection, generating a driving signal u for the first switch tube S1 gs,S1 and the fourth switch tube S4 driving signal u gs,S4 ; The first switch tube drive signal u gs,S1 Take the inversion and get the driving signal u of the second switch tube S2 gs,S2 and the driving signal u of the third switch tube S3 gs,S3 .

[0046] When the second port of the output filter circuit of the energy storage converter is connected to the high-frequency AC grid, the energy storage converter operates in the grid-connected mode, such as Figure 2 (b), the control method specifically comprises the following steps:

[0047] The grid voltage sampling value u of the energy storage converter g,f It is sent to the phase-locked device to obtain the grid voltage phase signal θ;

[0048] The grid current amplitude reference value I set by the energy storage converter g,ref , and the unit sinusoidal signal after the grid voltage phase signal θ is synchronized with the phase to obtain the grid current reference value i g,ref =I g,ref *sin(ωt+θ);

[0049] In the formula, ω o is the output voltage angular frequency.

[0050] The grid current sampling value i of the energy storage converter g,f and the grid current reference value i g,ref Compare and get the error signal i g,e ;

[0051] The error signal i g,e It is sent to the output current controller and passes through the bidirectional limiting link to obtain the sinusoidal modulation signal u rac ;

[0052] Generate a driving signal u for the first switch tube S1 gs,S1 and the fourth switch tube S4 driving signal u gs,S4 ; The first switch tube drive signal u gs,S1 Take the inversion and get the driving signal u of the second switch tube S2 gs,S2 and the driving signal u of the third switch tube S3 gs,S3 .

[0053] Furthermore, the voltage gain G of the inverter is U om / Uin =2M, where M = U rm / U cm =U om / U dc is the modulation ratio of the energy storage converter; where U rm is the sinusoidal modulated signal u rac The amplitude, U cm is the triangular carrier u c The amplitude, U om is the output voltage u of the energy storage converter o The fundamental amplitude, U dc is the DC bus voltage u dc The average value, U in is the input voltage u in The average value of .

[0054] Furthermore, the input filter inductor L in The inductance is as follows:

[0055]

[0056] Where P o is the output active power, ω o is the output voltage angular frequency, M is the modulation ratio of the energy storage converter, U in is the input voltage u in The average value of .

[0057] Below Figure 1 The working process of a single-phase boost high-frequency energy storage converter shown in (a) and (b) is explained. Since the working process of the energy storage converter in the off-grid mode and the grid-connected mode is exactly the same, only the off-grid mode is analyzed below.

[0058] To simplify the analysis, the following assumptions are made: The input filter capacitor C in , input filter inductor L in , DC bus capacitor C dc , output filter inductor L f , output filter capacitor C f , the first switch tube S1, the second switch tube S2, the third switch tube S3 and the fourth switch tube S4 are all ideal devices; the input voltage U in Constant, can be approximated as a constant voltage source; DC bus capacitance C dc Large enough to ignore the voltage ripple, the voltage at both ends is approximately constant, and it can be regarded as a constant voltage source; the DC bus capacitor C dc The negative pole and the negative pole of the input power supply are the zero potential reference points.

[0059] Based on the above assumptions, after entering the steady state, the working process of a single-phase boost high-frequency energy storage converter in a switching cycle of the positive half-cycle and the negative half-cycle of the power frequency can be divided into two modes. The working processes in the positive half-cycle and the negative half-cycle of the power frequency are as follows:

[0060] (1) Positive half cycle

[0061] In the positive half cycle of the power frequency, the equivalent circuits of each mode are as follows: Figure 3 As shown in (a)-(b), the main waveforms in a switching cycle are as follows Figure 5 (a) shown.

[0062] Mode 1, t0~t1 stage: (equivalent circuit as Figure 3 (a)

[0063] At time t0, the first switch tube S1 and the fourth switch tube S4 are turned on at the same time, and the input filter inductor L in Withstand reverse voltage U dc -U in , input filter inductor current i Lin (t) linearly decreases, input filter inductance L in and DC bus capacitor C dc At the same time, energy is provided to the load. At time t1, mode 1 ends. The calculation formulas for the input filter inductor current and the current of each switch tube are as follows:

[0064]

[0065]

[0066] Mode 2, t1~t2 stage: (equivalent circuit as Figure 3 (b)

[0067] At time t1, the first switch tube S1 and the fourth switch tube S4 are turned off, and the second switch tube S2 and the third switch tube S3 are turned on. in Withstand forward voltage U in , input filter inductor current i Lin (t) rises linearly, and at time t2, mode 2 ends. The input filter inductor current and the current calculation formula of each switch tube are as follows:

[0068]

[0069]

[0070] (2) Negative half cycle

[0071] In the negative half cycle of the power frequency cycle, the equivalent circuits of each mode are as follows: Figure 4As shown in (a)-(b), the main waveforms in a switching cycle are as follows Figure 5 (b) as shown.

[0072] Mode 1, t0~t1 stage: (equivalent circuit as Figure 4 (a)

[0073] At time t0, the second switch tube S2 and the third switch tube S3 are turned on at the same time, and the input filter inductor L in Withstand forward voltage U in , input filter inductor current i Lin (t) linearly increases, DC bus capacitance C dc Provide energy to the load, and at time t1, mode 1 ends. The current calculation formula of the input filter inductor and each switch tube is as follows:

[0074]

[0075]

[0076] Mode 2, t1~t2 stage: (equivalent circuit as Figure 4 (b)

[0077] At time t1, the second switch tube S2 and the third switch tube S3 are turned off, the first switch tube S1 and the fourth switch tube S4 are turned on, and the input filter inductor L in Withstand reverse voltage U dc -U in , input filter inductor current i Lin (t) linearly decreases, input filter inductance L in For DC bus capacitor C dc Charging is carried out, and at time t2, mode 2 ends. The current calculation formula of the input filter inductor and each switch tube is as follows:

[0078]

[0079]

[0080] DC gain analysis of the present invention: Assuming that the carrier frequency is much larger than the modulation wave frequency, the modulation wave in each switching cycle can be regarded as a constant value, then the equivalent duty cycle of each mode at time t is:

[0081]

[0082] Where, d S1 (t), d S2 (t), d S3 (t), d S4 (t) are the duty cycles when the switches S1, S2, S3, and S4 are turned on simultaneously.

[0083] In one power frequency cycle, the modulated wave is divided into N carrier cycles T s NT s =π / ω o When the switches S1 and S4 are turned on, the input filter inductor discharges; when the switches S2 and S3 are turned on, the input filter inductor charges. in The volt-second balance can be obtained:

[0084]

[0085] Substituting formula (9) into formula (10), we can obtain the following simplified formula:

[0086]

[0087] Therefore, the voltage gain of the inverter is:

[0088]

[0089] From formula (12), we can get the relationship curve between the inverter DC gain G and the modulation ratio M, as shown in Figure 6 As shown. It can be seen that the DC gain G of the inverter is linearly related to the modulation ratio M, and the DC gain G increases as the modulation ratio M increases.

[0090] The design process of the input filter inductor of the present invention is as follows:

[0091] The input filter inductor of the single-phase boost high-frequency energy storage converter proposed in the present invention always works in CCM mode, and the working process of the input filter inductor in the positive and negative half-cycles of the power frequency is similar, so only the positive half-cycle of the power frequency is analyzed here. In the positive half-cycle of the power frequency, the current change of the input filter inductor satisfies:

[0092]

[0093] In the positive half cycle, when the switches S1 and S4 are turned on, the input filter inductor discharges; when the switches S2 and S3 are turned on, the input filter inductor charges; therefore, in each switching cycle, the input filter inductor L in The current rise △i in+ and the drop △i in- They are:

[0094]

[0095] Substituting equations (11) and (14) into equation (13), we can obtain the following simplified equation:

[0096]

[0097] Assuming that the entire system has no loss and the output power is equal to the input power, the average value of the input current is:

[0098]

[0099] Because the average value of the input filter inductor current is equal to the average value of the input current, the current expression of the input filter inductor is:

[0100]

[0101] It is usually required that the peak-to-peak value of the input filter inductor current does not exceed 40% of its maximum average current for design. At this time, from formula (17), we can get:

[0102]

[0103] The specific embodiments of the present invention are given below, and the design indicators are as follows: DC input voltage U in =100V, output voltage frequency f o =1000Hz, switching frequency f s =50kHz, maximum output active power P o,max =500W, output voltage effective value U o =110V. When the energy storage converter operates at the maximum output power working state, substituting the design index into formula (18), the inductance of the input filter inductor can be obtained as:

[0104]

[0105] The actual input filter inductance L in =12.5mH.

[0106] In the off-grid mode, the present invention uses the Saber simulation software to simulate and verify the converter and control method of the present invention. The specific parameters of the main circuit energy storage element are as follows: the off-grid load is simulated by an inductive load, and the power factor of the load is DC bus capacitor C dc =220μF, input filter inductor L in =12.5mH, output filter inductor L f =1.1mH, output filter capacitor C f =2.2μH. The output voltage PI controller parameters and the output filter inductor current PI controller parameters are: k p1 =0.01, k i1 =7300 and k p2 =0.1, k i2 =1500.

[0107] Figure 7 The sinusoidal modulation signal u of the converter proposed by the present invention when working in off-grid mode is given as follows: rac , triangular carrier signal u c , input filter inductor current i Lin 、Input voltage U in , DC bus voltage U dc , output current i o And the output voltage u o Simulation waveform. As can be seen from the figure, the input filter inductor current pulsates at the output voltage frequency, the current average value is 5.536A, and the current peak-to-peak value is 2.176A, which basically satisfies the input filter inductor current relationship of formula (18), and is basically consistent with the theory. Under the design indicator of input voltage of 48V, the average value of the DC bus voltage is 95.308V, which approximately satisfies the relationship in formula (11) that the DC bus voltage is twice the input voltage; the effective value of the output voltage is 55.055V, and the effective value of the output current is 5.699A, which meets the design indicators and the requirements of dual closed-loop control voltage regulation. The phase of the output voltage leads the phase of the output current by 1 / 10 cycle, that is, 36, which basically meets the power factor

[0108] In the grid-connected mode, the present invention uses the Saber simulation software to simulate and verify the converter and its grid-connected mode control method of the present invention. The specific parameters of the main circuit energy storage element are as follows: the grid load is equivalent to an AC voltage source with a voltage and frequency of 110V / 1000Hz, and the DC bus capacitor C dc =220μF, input filter inductor L in =12.5mH, grid-connected filter inductor L g =2mH. The grid-connected current PI controller parameters are: k p =0.1, k i =210.

[0109] Figure 8 The sinusoidal modulation signal u of the converter proposed by the present invention when working in the grid-connected mode is given as follows: rac , triangular carrier signal u c , input filter inductor current i Lin 、Input voltage U in , DC bus voltage U dc , output current i g And the output voltage u g As can be seen from the figure, when connected to the grid, the energy storage converter of the present invention has two working modes: the battery supplies energy to the grid and the grid supplies energy to the battery. Figure 8It can be seen from (a) that the input filter inductor current pulsates at the output voltage frequency, and its average current is 5.67A. The effective value of the grid current is 4.56A, and it has the same frequency and direction as the grid voltage. At this time, the battery supplies energy to the grid through the energy storage converter; Figure 8 It can be seen from (b) that the input filter inductor current pulsates at the output voltage frequency, with an average current of -4.43A and a peak-to-peak current of 2.176A. The effective value of the grid current is 4.56A, and it is in the same frequency and opposite direction as the grid voltage. At this time, the grid charges the battery through the energy storage converter.

[0110] It can be seen from the above simulation results that the single-phase boost high-frequency energy storage inverter and control method proposed in the present invention have the following advantages: the inverter has the advantages of a small number of components, low cost, simple control, no circulating current, and the ability to suppress common-mode current, etc., and has good application prospects in high-frequency AC power grids and ultra-high-speed single-phase asynchronous motors.

[0111] 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 sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0112] The above embodiments are only used to help understand the method and core idea of ​​the present invention, but not to limit it. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A single-phase boost high-frequency energy storage converter, characterized in that: include: Input filter capacitor C in , input filter inductor L in , DC bus capacitor C dc , first switch tube S1, second switch tube S2, third switch tube S3 and fourth switch tube S4; input filter inductor L in One end of the input filter capacitor C in The positive electrode is connected to the positive pole of the energy storage converter as the positive input terminal; the input filter inductor L in The other end is connected to the source of the first switch tube S1 and the drain of the second switch tube S2; the input filter capacitor C in The negative electrode of the second switch tube S2, the source of the fourth switch tube S4 and the DC bus capacitor C dc The negative electrode of the DC bus capacitor C is connected to the negative electrode of the DC bus capacitor C as the negative input terminal of the energy storage converter; dc The positive electrode is connected to the drain of the first switching tube S1 and the drain of the third switching tube S3; the energy storage converter is connected to the output filter circuit, the first port of the output filter circuit is connected to the source of the third switching tube S3, the drain of the fourth switching tube S4, the source of the first switching tube S1, and the drain of the second switching tube S2, and the second port of the output filter circuit is connected to one of a high-frequency AC power grid, an ultra-high-speed asynchronous motor, and a load device.

2. A single-phase boost high-frequency energy storage converter according to claim 1, characterized in that: When the second port of the output filter circuit of the energy storage converter is connected to an ultra-high-speed asynchronous motor or a load device, the control method of the energy storage converter includes the following steps: The output voltage sampling value u of the energy storage converter o,f and the output voltage reference value u o,ref Compare and get the output voltage error signal u o,e ; Among them, u o,ref =U o,ref *sinω o t;U o,ref is the amplitude of the output voltage reference value, ω o is the output voltage angular frequency; The output voltage error signal u o,e It is sent to the output voltage controller and passes through the bidirectional limiting link to obtain the output filter inductor current reference value i Lf,ref ; The output filter inductor current reference value i Lf,ref and the output filter inductor current sampling value i Lf,f By comparison, the output filter inductor current error signal i Lf,e , sent to the output filter inductor current controller, and through the bidirectional limiting link, a sinusoidal modulated signal u is obtained. rac ; The sinusoidal modulated signal u rac With bipolar triangle carrier u c Intersection, generating the driving signal u of the first switch tube S1 gs,S1 and the driving signal u of the fourth switch tube S4 gs,S4 ; The first switch tube drive signal u gs,S1 Take the inversion and get the driving signal u of the second switch tube S2 gs,S2 and the driving signal u of the third switch tube S3 gs,S3 .

3. The single-phase boost high-frequency energy storage converter according to claim 1, characterized in that: When the second port of the output filter circuit of the energy storage converter is connected to the high-frequency AC grid, the control method of the energy storage converter The following steps are involved: The grid voltage sampling value u of the energy storage converter g,f It is sent to the phase-locked device to obtain the grid voltage phase signal θ; The grid current amplitude reference value I set by the energy storage converter g,ref Multiplying the unit sinusoidal signal after phase synchronization with the grid voltage phase signal θ, the grid current reference value i is obtained. g,ref =I g,ref *sin(ω o t+θ); Where, ω o is the output voltage angular frequency; The grid current sampling value i of the energy storage converter is g,f and the grid current reference value i g,ref Compare and get the grid current error signal i g,e ; The grid current error signal i g,e It is sent to the output current controller and passes through the bidirectional limiting link to obtain the sinusoidal modulated signal u rac ; The sinusoidal modulated signal u rac With bipolar triangle carrier u c Intersection, generating the driving signal u of the first switch tube S1 gs,S1 and the driving signal u of the fourth switch tube S4 gs,S4 ; The first switch tube drive signal u gs,S1 Take the inversion and get the driving signal u of the second switch tube S2 gs,S2 and the driving signal u of the third switch tube S3 gs,S3 .

4. A single-phase boost high-frequency energy storage converter according to claim 2 or 3, characterized in that: The voltage gain G of the energy storage converter is U om / U in =2M, where M is the modulation ratio of the energy storage converter, M=U rm / U cm =U om / U dc ;U rm is the sinusoidal modulated signal u rac The amplitude, U cm is the triangular carrier u c The amplitude, U om is the output voltage u of the energy storage converter o The fundamental amplitude, U dc is the DC bus voltage u dc The average value, U in is the input voltage u in The average value of .

5. A single-phase boost high-frequency energy storage converter according to claim 2 or 3, characterized in that: The input filter inductor L in The inductance is as follows: Where, P o is the output active power, M is the modulation ratio of the energy storage converter, U in is the input voltage u in The average value of .

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