CN103178737A - Hysteresis control method for keeping midpoint voltage balance of three-level photovoltaic inverter - Google Patents
Hysteresis control method for keeping midpoint voltage balance of three-level photovoltaic inverter Download PDFInfo
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- CN103178737A CN103178737A CN2013100959470A CN201310095947A CN103178737A CN 103178737 A CN103178737 A CN 103178737A CN 2013100959470 A CN2013100959470 A CN 2013100959470A CN 201310095947 A CN201310095947 A CN 201310095947A CN 103178737 A CN103178737 A CN 103178737A
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
Abstract
The invention belongs to the field of inverters, and particularly relates to a hysteresis control method for keeping the midpoint voltage balance of a three-level photovoltaic inverter. The hysteresis control method for keeping the midpoint voltage balance of the three-level photovoltaic inverter comprises an EMI (electro-magnetic interference) filter connected with a cell panel, a Boost circuit, a three-level inverter, a low-pass filter, and an EMI filter connected with a mains supply, wherein the EMI filter is used for filtering out the interference of high-frequency noise of a direct current of the cell panel, and the direct current enters in the Boost circuit and then increases a DC (direct-current) voltage, then enters in the three-level inverter and converts a DC to an AC (alternating-current), and then is conveyed to the EMI filter connected with the mains supply via the low-pass filter. The method further comprises a control circuit based on a DSP (digital signal processor) and a CPLD (complex programmable logic device). The method disclosed by the invention has the advantage of being finished in each interrupt handling program of software without increasing additional time expenditure and much computation quantity, so that the program stably runs in a reasonable hysteresis range.
Description
Technical field
The invention belongs to the inverter field, specifically a kind of hysteresis control method thereof of keeping three level photovoltaic inverter neutral point voltage balances.
Background technology
At present in the industry cycle in 10～20kW power grade photovoltaic synchronization inverter system, its main circuit topology is mainly that Boost+ is based on the inverter two-layer configuration of three Level Technology, wherein one of three level large key technology is exactly to keep the balance of DC side mid-point voltage always, but due to the difference of component parameters and the error of output control, unavoidable mid-point voltage can be uneven, if do not controlled, will run down, greatly reduce the waveform quality of inverter current until whole three level system are converted to two level.For this present situation, industry mainly contains two class control strategies at present: the one, and utilize prime Boost to control, recently constantly regulate by the duty of controlling Boost, but so just necessarily requiring prime is two-way Boost circuit, if when two-way has all required the MPPT function, will attend to one thing and lose sight of another, sacrifice a kind of function; Another strategy is exactly to detect in real time the electric current that flows through mid point, make the quantity of electric charge of up and down electric capacity reach a dynamic equilibrium by a series of based on the space vector transformation calculations in conjunction with variation, although do so in theory and can accomplish accurate control, increased like this hardware cost and software amount of calculation.
Summary of the invention
The present invention is directed to the shortcoming of above-mentioned middle existence, propose a kind of saving time and the hysteresis control method thereof of keeping three level photovoltaic inverter neutral point voltage balances based on the real time altering small vector conducting factor of operand.
The invention provides following technical scheme:
Keep the hysteresis control method thereof of three level photovoltaic inverter neutral point voltage balances, it comprises electromagnetic interface filter, Boost booster circuit, three-level inverter, the low pass filter that connects cell panel and the electromagnetic interface filter that connects civil power; The interference of the galvanic high-frequency noise of electromagnetic interface filter filtering cell panel, direct current improves dc voltage after entering the Boost booster circuit, then enter three-level inverter the DC current conversion is become the AC electric current, then be transported to by low pass filter the electromagnetic interface filter that connects civil power, also comprise the control circuit based on DSP and CPLD, the control method of this control circuit is as follows:
A, according to the amplitude of operational order computer memory vector and the step of phase angle;
B, judge that this vector is in which sector and little leg-of-mutton step;
The step of the ON time of c, each 7 segmentation conducting sequences of calculating;
D, judge that the unbalance of neutral-point voltage amount whether in-1%-1% scope, is two small vector conductings 50% when-1%-1% scope; Not to judge whether forward migration of mid-point voltage when-1%-1% scope;
E, according in the d step, mid-point voltage is forward migration, will bear small vector conducting ratio according to the side-play amount of mid-point voltage and continue gradually increase or reduce on a upper computing cycle basis; When mid-point voltage is not forward migration, according to the side-play amount of mid-point voltage, positive small vector conducting ratio is continued increase or reduce gradually on a upper computing cycle basis;
F, burst pulse handling procedure, PWM output.
Negative small vector ratio described in step e, positive small vector ratio are all greater than 50%.
Advantage of the present invention is that this method is directly completed in each interrupt handling routine of software, can not increase other time overhead and more operand, makes calling program stable operation in a rational stagnant ring scope.
Description of drawings
Fig. 1 is structural representation of the present invention;
Fig. 2 is for adjusting in real time small vector conducting factor schematic diagram (take positive small vector as example);
Fig. 3 is 3 level space vector corresponding diagram (the 3rd triangle is as example take the first sector);
Abandon burst pulse schematic diagram (the 3rd triangle is as example take the first sector) when Fig. 4 conducting factor is too small, wherein (a) is 7 normal segmentation conducting sequences, (b) simply process the burst pulse mode, the processing burst pulse mode of (c) taking in the present invention;
The T-shaped three level topological structures of Fig. 5;
Fig. 6 the inventive method flow chart;
Embodiment
As shown in Fig. 2 (take positive small vector as example), the present invention adopts 7 segmentation conducting sequences, in order to reduce switching loss, each sequence is from small vector, and small vector always occurs in pairs, another one must be the redundancy vector, and core of the present invention is exactly the conducting factor of two small vectors that occur in pairs.If mid-point voltage is in a scope of comparatively accepting such as 1% in theory, the conducting ratio of each small vector is exactly respectively to account for 0.5, just makes not to be partial to any one dc bus capacitor.Do not reach 2% if mid-point voltage to the forward is offset, the conducting ratio of so corresponding positive small vector just drops to 0.4, and the ratio of negative small vector just brings up to 0.6, if continue forward migration, will continue to go to regulate according to this trend; If unbalance of neutral-point voltage in 1%, just stops revising the conducting factor, if oppositely skew, with regard to the conducting factor of the positive small vector of corresponding increase.If the conducting factor reaches 0.9 or 0.1, just stop changing the conducting factor, will cause burst pulse because ON time is too short, at this moment just directly abandon the short small vector of this ON time, but do as a whole, must abandon simultaneously the conducting sequence of three-phase, otherwise will make the output waveform distortion, as shown in Fig. 3 and Fig. 4 (take the 3rd of the first sector triangle as example).If this moment, mid-point voltage still was offset increasing, even exceed protection range, so just must stop inverter work, think its fault, carry out the investigation of other side.
Keep the hysteresis control method thereof of three level photovoltaic inverter neutral point voltage balances, it comprises electromagnetic interface filter, Boost booster circuit, three-level inverter, the low pass filter that connects cell panel and the electromagnetic interface filter that connects civil power; The interference of the galvanic high-frequency noise of electromagnetic interface filter filtering cell panel, direct current improves dc voltage after entering the Boost booster circuit, then enter three-level inverter the DC current conversion is become the AC electric current, then be transported to by low pass filter the electromagnetic interface filter that connects civil power, also comprise the control circuit based on DSP and CPLD, the control method of this control circuit is as follows:
A, according to the amplitude of operational order computer memory vector and the step of phase angle;
B, judge that this vector is in which sector and little leg-of-mutton step;
The step of the ON time of c, each 7 segmentation conducting sequences of calculating;
D, judge that the unbalance of neutral-point voltage amount whether in-1%-1% scope, is two small vector conductings 50% when-1%-1% scope; Not to judge whether forward migration of mid-point voltage when-1%-1% scope;
E, according in the d step, mid-point voltage is forward migration, will bear small vector conducting ratio according to the side-play amount of mid-point voltage and continue gradually increase or reduce on a upper computing cycle basis; When mid-point voltage is not forward migration, according to the side-play amount of mid-point voltage, positive small vector conducting ratio is continued increase or reduce gradually on a upper computing cycle basis;
F, burst pulse handling procedure, PWM output.
Negative small vector ratio described in step e, positive small vector ratio are all greater than 50%
Claims (2)
1. keep the hysteresis control method thereof of three level photovoltaic inverter neutral point voltage balances, it comprises electromagnetic interface filter, Boost booster circuit, three-level inverter, the low pass filter that connects cell panel and the electromagnetic interface filter that connects civil power; The interference of the galvanic high-frequency noise of electromagnetic interface filter filtering cell panel, direct current improves dc voltage after entering the Boost booster circuit, then enter three-level inverter the DC current conversion is become the AC electric current, then be transported to by low pass filter the electromagnetic interface filter that connects civil power, it is characterized in that: also comprise the control circuit based on DSP and CPLD, the control method of this control circuit is as follows:
A, according to the amplitude of operational order computer memory vector and the step of phase angle;
B, judge that this vector is in which sector and little leg-of-mutton step;
The step of the ON time of c, each 7 segmentation conducting sequences of calculating;
D, judge that the unbalance of neutral-point voltage amount whether in-1%-1% scope, is two small vector conductings 50% when-1%-1% scope; Not to judge whether forward migration of mid-point voltage when-1%-1% scope;
E, according in the d step, mid-point voltage is forward migration, will bear small vector conducting ratio according to the side-play amount of mid-point voltage and continue gradually increase or reduce on a upper computing cycle basis; When mid-point voltage is not forward migration, according to the side-play amount of mid-point voltage, positive small vector conducting ratio is continued increase or reduce gradually on a upper computing cycle basis;
F, burst pulse handling procedure, PWM output.
2. the hysteresis control method thereof of keeping three level photovoltaic inverter neutral point voltage balances according to claim 1 is characterized in that: the negative small vector ratio described in step e, positive small vector ratio are all greater than 50%.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103916008A (en) * | 2014-04-22 | 2014-07-09 | 扬州大学 | Output capacitance voltage-sharing control system and control method for three-level DC converter |
| CN104253471A (en) * | 2013-06-28 | 2014-12-31 | 比亚迪股份有限公司 | Charging system and charging control method of electric vehicle |
| CN105391328A (en) * | 2015-10-30 | 2016-03-09 | 上能电气股份有限公司 | Hysteresis loop control method for three-level inverter |
| CN107994795A (en) * | 2017-12-08 | 2018-05-04 | 中国船舶工业系统工程研究院 | A kind of three-level Boost converter neutral-point potential balance control method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101834443A (en) * | 2010-04-22 | 2010-09-15 | 河源市雅达电子有限公司 | Method for balancing three-level direct current midpoint voltage by using time factor |
| CN102522911A (en) * | 2011-11-25 | 2012-06-27 | 华为技术有限公司 | Inverting device and solar PV (Photovoltaic) grid-connected system applying same |
| CN102570883A (en) * | 2011-06-03 | 2012-07-11 | 深圳市英威腾电气股份有限公司 | Three-level inverter narrow-pulse elimination and midpoint voltage control method and device |
| CN102916438A (en) * | 2012-07-16 | 2013-02-06 | 上海电力学院 | Photovoltaic power generation control system and photovoltaic power generation control method based on three-level inverter |
-
2013
- 2013-03-25 CN CN2013100959470A patent/CN103178737A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101834443A (en) * | 2010-04-22 | 2010-09-15 | 河源市雅达电子有限公司 | Method for balancing three-level direct current midpoint voltage by using time factor |
| CN102570883A (en) * | 2011-06-03 | 2012-07-11 | 深圳市英威腾电气股份有限公司 | Three-level inverter narrow-pulse elimination and midpoint voltage control method and device |
| CN102522911A (en) * | 2011-11-25 | 2012-06-27 | 华为技术有限公司 | Inverting device and solar PV (Photovoltaic) grid-connected system applying same |
| CN102916438A (en) * | 2012-07-16 | 2013-02-06 | 上海电力学院 | Photovoltaic power generation control system and photovoltaic power generation control method based on three-level inverter |
Non-Patent Citations (2)
| Title |
|---|
| 叶宗彬等: "三电平整流器中性点平衡控制策略的研究", 《电力电子技术》 * |
| 谭国俊等: "三电平变频器控制策略的仿真与实现", 《电力电子技术》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104253471A (en) * | 2013-06-28 | 2014-12-31 | 比亚迪股份有限公司 | Charging system and charging control method of electric vehicle |
| CN104253471B (en) * | 2013-06-28 | 2017-02-22 | 比亚迪股份有限公司 | Charging system and charging control method of electric vehicle |
| US10173543B2 (en) | 2013-06-28 | 2019-01-08 | Byd Company Limited | Charging system for electric vehicle and method for controlling charging of electric vehicle |
| CN103916008A (en) * | 2014-04-22 | 2014-07-09 | 扬州大学 | Output capacitance voltage-sharing control system and control method for three-level DC converter |
| CN105391328A (en) * | 2015-10-30 | 2016-03-09 | 上能电气股份有限公司 | Hysteresis loop control method for three-level inverter |
| CN105391328B (en) * | 2015-10-30 | 2018-11-09 | 上能电气股份有限公司 | A kind of hysteresis control method thereof of three-level inverter |
| CN107994795A (en) * | 2017-12-08 | 2018-05-04 | 中国船舶工业系统工程研究院 | A kind of three-level Boost converter neutral-point potential balance control method |
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Application publication date: 20130626 |