CN2655488Y - Integrated compensator for power system - Google Patents
Integrated compensator for power system Download PDFInfo
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- CN2655488Y CN2655488Y CN 200320117330 CN200320117330U CN2655488Y CN 2655488 Y CN2655488 Y CN 2655488Y CN 200320117330 CN200320117330 CN 200320117330 CN 200320117330 U CN200320117330 U CN 200320117330U CN 2655488 Y CN2655488 Y CN 2655488Y
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Abstract
An electric system integrated compensation device mainly comprises a net side voltage detecting device, a net side circuit detecting device, a loading side base wave circuit extracting device, a data signal processor DSP and a control system based on the DSP, a pulse width modulation generator, an inverter and an LC filter circuit. The utility model mainly adopts the structure and the control method combined of the non-smooth non-linear control strategy and an extending condition observer, the extending condition observer is used to observe the output or derivative or unknown inner and outer interference to change the reversal phase compensation of the harmonic to the tracing of ideal sine signal, meanwhile the main circuit of a pressure control reactor is adopted to realize the reactive-load dynamic compensation, which not only can lower the capacity of the inverter to the lowest, but also realizes the tracing of the ideal sine signal of the given phase according to the control of the reactor voltage to obtain the function of filter, which fully ensures the utility model can reliably integrate the filter source, no filter source and the reactive-load dynamic together.
Description
Technical field
The utility model belongs to the electric power project engineering field, particularly relates to a kind of comprehensive compensating device by the active and passive electric power system that constitutes.
Background technology
Develop rapidly along with power technology, various power electronic equipments have obtained to use widely in industrial neighborhood such as electric power system, metallurgy, iron and steel, chemical industry and fields such as traffic, building automatic and family life, and this just makes the harmonic pollution situation in the electrical network serious day by day.And, be used to improve the easy and system impedance generation resonance of capacitor of power factor in the electrical network, thereby cause harmonic wave to amplify.This has all increased the weight of the harmonic pollution in the electrical network.
Harmonic wave in the electrical network not only endangers electrical network itself but also endangers its peripheral equipment.Harmonic wave in the electrical network makes the efficient of production, transmission and the utilization of electric energy reduce on the one hand, make device of overheating of electrical, produce vibration and noise, and ageing of insulation, useful life are reduced, itself in addition break down or burn.Simultaneously, harmonic wave can cause that also parallel resonance or series resonance appear in the electric power system part, and harmonic content is amplified, and causes equipment burnouts such as capacitor.Harmonic wave also can cause relay protection and automatics misoperation, and electric energy metrical is caused confusion.For the electric power system outside, harmonic wave can produce serious disturbance to communication apparatus and electronic equipment.
Harmonic pollution situation in the electrical network is serious day by day, thereby, for the also increase day by day of demand of harmonic treating apparatus.And harmonic wave control also is the important component part of building " green electrical network ".Present harmonic treating apparatus mainly contains two big classes: passive filtration unit and active filter.
Passive filtration unit wherein can be referring to " harmonic analysis of HVDC (High Voltage Direct Current) transmission system and filtering " book of being published by hydraulic and electric engineering publishing house in August, 1994, and its circuit structure diagram is seen Fig. 1, and its equivalent circuit diagram under the harmonic wave effect as shown in Figure 2.Passive filter has advantages such as sturdy and durable, cheap, but can't solve because of resonance cause certain subharmonic problem of amplifying.Except that this shortcoming, passive filter also has following shortcoming:
1, the compensation performance difference is because the parameter of capacitor and inductance exists error; In running, will the filter filtering effect be degenerated because of the aging influence of variation, self-heating and the capacitor insulation of environment temperature changes;
2, bad dynamic performance is when the load current dynamic change, and it is to the inhibition weak effect of harmonic current;
3, compensation performance is subjected to the influence of system impedance, and the variation of system impedance will influence its filter effect;
Even 4 in ideal conditions, also can only produce reasonable inhibition effect to the specific times harmonic electric current;
5, bulky, it is more to take up room.
Existing active filter can be referring to nineteen ninety-five " Toyo Electric Mfg Co., Ltd.'s product description ".Its theory diagram as shown in Figure 3.Its basic principle is: by control active filter is injected with load harmonic wave size is consistent but the electric current that phase place is opposite to electrical network, so just can make power network current is sine wave, thereby, realized the purpose of harmonic carcellation electric current.
The shortcoming of present active power filtering technology can mainly contain referring to Tsing-Hua University's thesis for the doctorate " research of novel combined power filtering system " in 1997:
1, because the fundamental voltage of AC power is applied directly on the inverter, and offset current provides by inverter fully, therefore, the capacity of inverter must be very big;
2, because the power electronic device cost is higher at present, the price of this system is very expensive;
3,, need further to improve because testing circuit is subject to the influence that error is disperseed and debugged to device parameters, and this can influence its compensation performance;
4, because active filter adopts brand-new structure, be unsuitable for original passive filtration unit is transformed.
At the problem that exists in above-mentioned independently passive filtration unit and the active filter, that Chinese patent ZL00109624.9 (publication number CN1274977A) discloses is a kind of the combined power filter with both of passive formation " active and ", its circuit theory as shown in Figure 4, it is mainly by active filter, passive filter, transformer and control circuit are formed, one end and the electrical network of passive filter link, one end of the other end and transformer secondary output links, the mutual short circuit of the other end of transformer secondary output together, the mid point of inverter bridge leg links in one end on the former limit of transformer and the active filter, and the mutual short circuit of the other end on former limit together.Control circuit comprises current transformer, harmonics detection circuit, adjuster, control circuit for pulse-width modulation and drive circuit.Current transformer is transformed into input harmonics testing circuit behind the voltage signal with the current signal of electrical network, obtain the mains by harmonics current signal, this signal is sent into adjuster, the command signal of the feedback signal of the capacitance voltage in active filter controlled electric current after regulating, and send into control circuit for pulse-width modulation, symbol according to command signal produces control signal corresponding, promptly when the command signal of a phase wherein greater than zero the time, produce a signal, send into drive circuit, through shaping, amplify, after the isolation, make the switching tube conducting of brachium pontis on the inverter bridge with this mutually corresponding active filter, the switching tube of following brachium pontis turn-offs; If less than zero the time, produce a signal, send into drive circuit, after shaping, amplification, isolation, make the switching tube shutoff of bridge wall on the inverter bridge with this corresponding active filter, the switching tube conducting of following brachium pontis, with the output voltage of control active power filtering, realize filtering.The advantage of this combined power filter with both be cost lower, do not have certain economic practicality and filtering performance better, can not produce serial or parallel connection resonance, but the shortcoming of its existence is: at first must detect the higher harmonic wave of high frequency content owing to it, the difficulty height and the accuracy that detect are low, in this design, consider the filter effect of electrical network emphatically in addition owing to it, power factor to system is considered, therefore the weak effect of its reactive power compensation can not solve filtering and idle Comprehensive Control fully.
The Han Jingqing researcher of CAS Institute System Science Research has proposed differential and the interference volume of extended state observer (ESO) in order to observation output signal, output signal in nineteen ninety-five, see document " extended state observer of the uncertain object of a class ", " control and decision-making ", Vol.10 (1), 1995; In the same year, Han Jingqing researcher has also proposed nonlinear state Error Feedback control law (NLSEF), follows the tracks of and the interference compensation problem in order to resolution system, see document " nonlinear state Error Feedback control law-NLSEF ", " control and decision-making ", Vol.10 (3), 1995.ESO and NLSEF see the description in the embodiment for details.
Clear ESO that proposes of Han Jing and NLSEF provide the necessary technology instrument for the simple nonlinear Control that realizes system.
Summary of the invention
The purpose of this utility model is the problem at above-mentioned existence, a kind of strategy that adopts non-linear rough FEEDBACK CONTROL and extended state observer to combine is provided, both active power filtering and passive filtering was combined together, realize the comprehensive compensation of power factor and filtering simultaneously with same main circuit again and comprehensive compensation is effective, simple in structure, realize electric power system comprehensive compensating device easy, with low cost.
The technical solution of the utility model is achieved in that
A kind of electric power system comprehensive compensating device is characterized in comprising:
The voltage on line side checkout gear is used to detect and extract the sinusoidal voltage phase place of net side;
The current on line side checkout gear is used to detect and extract the current waveform of net side;
Load-side fundamental current extraction element is used for detecting and extraction load-side fundamental current amplitude;
Digital signal processor DSP is a jumbo microcomputer able to programme, and there is analog to digital converter inside, can become digital signal to the sampled analog signal by analog to digital converter, by the digital signal of the controlled rule of control algolithm;
Based on the control system of DSP, mainly comprise nonlinear state Error Feedback controller (NLSEF) and extended state observer (ESO), ESO is mainly used in the differential and the interference of estimated output signal, output signal; NLSEF carries out nonlinear combination control to the differential of error signal and error signal, to realize signal trace and to disturb and suppress;
Pwm generator is used for the pulse drive signal according to a driving inverter of control signal generation;
Inverter is used for according to pulse drive signal with the voltage on the L of control LC filter circuit;
The LC filter circuit is used for filtering load-side harmonic wave and the adjusting by its voltage reaches the purpose of regulating the electric power system power factor.
Wherein, each input of voltage on line side checkout gear is attempted by on the electrical network, and its output converts appropriate signal to through sample circuit, sends into DSP, and the analog to digital converter by DSP inside obtains digital signal corresponding.Current on line side checkout gear and load-side current sensing means are connected on each power transmission line of net side, same process signal sample circuit and analog to digital converter obtain its digital signal, based on the control system of DSP above-mentioned each signal are controlled to realize signal trace and to disturb and suppress.Its concrete control mode is as follows: the detection by the voltage on line side phase signal obtains net side reference current phase place, the detection by load-side electric current fundamental component obtains the amplitude of net side reference current, thereby obtains net side reference current signal and differential signal thereof.Be that to generate three state variables be current on line side signal z for the output of the extended state observer ESO of input with the current on line side signal
1And differential signal z
2And interference volume z
3, net side reference current and differential signal thereof and current on line side and differential signal thereof are made comparisons, obtain error ε
1And ε
2, construct appropriate about ε
1And ε
2Nonlinear function, thereby obtain nonlinear state Error Feedback control (NLSEF) signal u
0/ b
0(b
0Be gain), it is a signal of control signal, is used to realize signal trace; Utilize the z of ESO output
3Can generate another component-z of control signal
3/ b
0, be used to suppress the internal and external interference of system.With above-mentioned two control component combination, controlled signal u (t), here-u (t) is the differential of inverter AC side voltage, general-u (t) integration just obtains the voltage of inverter AC side.Utilizing pulse modulation technology (PWM), make DSP output appropriate signals control Driver Circuit, is the negative value of ∫ u (τ) d τ with the output voltage of guaranteeing the inverter AC side.Utilize the inverter output voltage signal, through smoothing reactor L
1, the voltage on the control LC filter circuit on the inductance L.
The utility model is owing to adopt rough non-linear control strategy and extended state observer structure combining and control method, utilize extended state observer with observation output and differential and unknown inside and outside interference, the antiphase compensation of harmonic wave is become the tracking of ideal sinusoidal signal, thereby needn't detect the more load current harmonic component of high frequency content, reduce the detection difficulty of harmonic wave.Because adopt the main circuit of voltage-controlled reactor formula to realize idle dynamic compensation, it is minimum both the inverter capacity to be reduced to, thereby saves cost; Realize that by the control reactor voltage net side is to the tracking of phase bit to the ideal sinusoidal signal again, reach the effect of filtering, guarantee that fully it can either combine active power filtering and passive filtering together reliably, solve the problem that certain subharmonic that causes because of resonance of existing in the passive filtering amplifies effectively, and the expensive problem that exists in the active power filtering.Thereby make this main circuit both as reactive-load dynamic compensation, play filter action again, reach the purpose of this utility model.
Describe structure of the present utility model and operation principle and process in detail below in conjunction with accompanying drawing:
Description of drawings
Fig. 1 is the structural representation of existing passive filter;
Fig. 2 is the equivalent circuit diagram of existing passive filter;
Fig. 3 is the theory diagram of existing active filter;
Fig. 4 is the electrical schematic diagram of the combined power filter with both of existing passive and active formation;
Fig. 5 is that structure of the present utility model is formed schematic diagram;
Fig. 6 is a control structure schematic diagram of the present utility model.
Embodiment
As Fig. 5, shown in Figure 6, electric power system comprehensive compensating device described in the utility model comprises:
The voltage on line side checkout gear is used to detect and extract the sinusoidal voltage phase place of net side;
The current on line side checkout gear is used to detect and extract the current waveform of net side;
Load-side fundamental current extraction element is used for detecting and extraction load-side fundamental current amplitude;
Digital signal processor DSP, it is a kind of jumbo microcomputer able to programme, there is analog to digital converter inside, can become digital signal to the sampled analog signal by analog to digital converter, by the digital signal of the controlled rule of control algolithm;
Based on the control system of DSP, mainly comprise nonlinear state Error Feedback controller (NLSEF) and extended state observer (ESO).ESO is mainly used in the differential and the interference of estimated output signal, output signal; NLSEF carries out nonlinear combination control to the differential of error signal and error signal, to realize signal trace and to disturb and suppress; Wherein the mentality of designing of the control of ESO and NLSEF is:
For ESO:
Consider following second-order system:
Or
x
1, x
2Be state variable, y is output, and w is for disturbing, and u is for control, concerning control system, as w (t) and f (t, x
1, x
2, w) known, state observer just can show.
Can design following nonlinear observer and estimate the state variable (x of following formula
1, x
2) and f (t, x
1, x
2, w):
β wherein
01, β
02, β
03Be the observer gain, b
0Be gain, g
1, g
2, g
3Be appropriate nonlinear function, make z
1, z
2, z
3Satisfy:
Wherein ε is a little positive constant.
For NLSEF:
ε
1=v
1-z
1, ε
2=v
2-z
2For with reference to error and differential thereof between input and the system's output, select suitable nonlinear function h
1, h
2And parameter beta
1, β
2, constitute controller u
0=β
1h
1(ε
1)+β
2h
2(ε
2).
Usually nonlinear combination is as follows:
u
0=β
1Fal (e
2, α
1, δ
1)+β
2Fal (e
3, α
2, δ
2) e wherein
2=v
1-z
1, e
3=v
2-z
2, u=u
0/ b
0-z
3/ b
0
Nonlinear function is:
As shown in Figure 6:
i
* sBe reference current, u
sSuppose it is sinusoidal, v
cBe inverter direct-flow side voltage, u is a control signal, v
cU is an inverter AC side voltage
i
sBe state variable, make i
L=i
s *-i
ω, following formula just becomes the structure of second-order system so:
Wherein
Compare second-order system, f (t, x as can be known
1, x
2,, w) forming by two parts, first is:
Second portion is:
Comprise some owing to parameter perturbation and not modeling produce dynamically, f
2Outer disturbing when (w (t)) then represented the variation of reflected load electric current ,-v
cDu/dt is equivalent to control signal, determines-v
cCan get the control signal of inverter AC side voltage behind the du/dt by the back integrator.
Pwm generator is used for the pulse drive signal according to a driving inverter of control signal generation;
Inverter is used for according to pulse drive signal with the voltage on the L of control LC filter circuit;
The LC filter circuit is used for filtering load-side harmonic wave and the adjusting by its voltage reaches the purpose of regulating the electric power system power factor;
Wherein, each input of voltage on line side checkout gear is attempted by on the electrical network, and its output converts appropriate signal to through sample circuit, sends into DSP, and the analog to digital converter by DSP inside obtains digital signal corresponding.Current on line side checkout gear and load-side current sensing means are connected on each power transmission line of net side, obtain its digital signal through signal sample circuit and analog to digital converter equally.Program on the DSP is controlled these signals.Concrete control mode is as follows: the detection by the voltage on line side phase signal obtains net side reference current phase place, the detection by load-side electric current fundamental component obtains the amplitude of net side reference current, thereby obtains net side reference current signal and differential signal thereof.Be that to generate three state variables be current on line side signal z for the output of the extended state observer ESO of input with the current on line side signal
1And differential signal z
2And interference volume z
3, net side reference current and differential signal thereof and current on line side and differential signal thereof are made comparisons, obtain error ε
1And ε
2, construct appropriate about ε
1And ε
2Nonlinear function, thereby obtain nonlinear state Error Feedback control (NLSEF) signal u
0/ b
0(b
0Be gain), it is that a signal of control signal is used to realize signal trace; Utilize the z of ESO output
3Can generate another component-z of control signal
3/ b
0, be used to suppress the internal and external interference of system.With above-mentioned two control component combination, controlled signal u (t), here-u (t) is the differential of inverter AC side voltage, general-u (t) integration just obtains the voltage of inverter AC side.Utilizing pulse modulation technology (PWM), make DSP output appropriate signals control Driver Circuit, is the negative value of ∫ u (τ) d τ with the output voltage of guaranteeing the inverter AC side.Utilize the inverter output voltage signal, through smoothing reactor L
1, the voltage on the control LC filter circuit on the inductance L.
The implementation method of electric power system comprehensive compensating device described in the utility model is: may further comprise the steps:
1), by voltage on line side checkout gear, load-side fundamental current extraction element, supply voltage phase signal and load current fundamental frequency amplitude signal through sample circuit obtains through the analog to digital converter of DSP, obtain its digital signal.In control algolithm, with the amplitude of load-side fundamental current as the reference current i
s *Amplitude, the voltage-phase that the voltage on line side checkout gear is extracted is as the i of reference electric current
s *Phase place (also can make i
s *Phase lag voltage-phase low-angle, i.e. a undercompensation), obtain reference current i
s *And differential i
s *';
2), the current i that the current on line side checkout gear is obtained through sample circuit
s, become digital signal through the analog to digital converter of DSP.In control algolithm, the current on line side signal is as the input signal of ESO, and the output of ESO generates three state variables, i.e. current on line side signal z
1, z
1Differential signal z
2And interference volume z
3
3), net side reference current and differential signal thereof and current on line side and differential signal thereof are made comparisons, obtain error ε
1And ε
2,
4), structure is appropriate in ε
1And ε
2Nonlinear function, thereby obtain NLSEF control signal u
0/ b
0(b
0Be gain), it is a signal of control signal, is used to realize signal trace;
5), utilize the z of ESO output
3Can generate another component-z of control signal
3/ b
0, be used to suppress the internal and external interference of system.
6), with above-mentioned two control component combination, controlled signal u (t), here-u (t) is the differential of inverter AC side voltage, general-u (t) integration just obtains the voltage of inverter AC side.
7), utilize pulse modulation technology (PWM), make DSP output appropriate signals control Driver Circuit, be the negative value of ∫ u (τ) d τ with the output voltage of guaranteeing the inverter AC side.Utilize the inverter output voltage signal, through smoothing reactor L
1, the voltage on the control LC filter branch inductance L, thus realize the tracking of actual current to reference current.
Claims (1)
1, a kind of electric power system comprehensive compensating device is characterized in that comprising:
The voltage on line side checkout gear is used to detect and extract the sinusoidal voltage phase place of net side;
The current on line side checkout gear is used to detect and extract the current waveform of net side;
Load-side fundamental current extraction element is used for detecting and extraction load-side fundamental current amplitude;
Digital signal processor DSP is a jumbo microcomputer able to programme, and there is analog to digital converter inside, can become digital signal to the sampled analog signal by analog to digital converter, by the digital signal of the controlled rule of control algolithm;
Based on the control system of DSP, mainly comprise nonlinear state Error Feedback controller (NLSEF) and extended state observer (ESO), ESO is mainly used in the differential and the interference of estimated output signal, output signal; NLSEF carries out nonlinear combination control to the differential of error signal and error signal, to realize signal trace and to disturb and suppress;
Pwm generator is used for the pulse drive signal according to a driving inverter of control signal generation;
Inverter is used for according to pulse drive signal with the voltage on the L of control LC filter circuit;
The LC filter circuit is used for filtering load-side harmonic wave and the adjusting by its voltage reaches the purpose of regulating the electric power system power factor.
Wherein, each input of voltage on line side checkout gear is attempted by on the electrical network, its output converts appropriate signal to through sample circuit, send into DSP, analog to digital converter by DSP inside obtains digital signal corresponding, current on line side checkout gear and load-side current sensing means are connected on each power transmission line of net side, obtain its digital signal through signal sample circuit and analog to digital converter equally, based on the control system of DSP above-mentioned each signal are controlled to realize signal trace and to disturb and suppress.
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|---|---|---|---|
| CN 200320117330 CN2655488Y (en) | 2003-10-24 | 2003-10-24 | Integrated compensator for power system |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100362739C (en) * | 2005-09-30 | 2008-01-16 | 武汉大学 | Method and device for producing electric motor arbitrary mechanical characteristic based on PWM technique |
| CN100369344C (en) * | 2003-10-24 | 2008-02-13 | 华南理工大学 | Synthetized compensation device in electric power system and synthetized compensation method |
| CN101212140B (en) * | 2006-12-29 | 2010-12-29 | 鸿富锦精密工业（深圳）有限公司 | Automatic power factor compensator |
| CN102082442A (en) * | 2011-03-14 | 2011-06-01 | 丹东欣泰电气股份有限公司 | High-voltage static var generator (SVG) without starting circuit and method for connecting SVG to power grid |
| CN101252337B (en) * | 2007-02-20 | 2013-04-24 | 通用汽车环球科技运作公司 | Reduction of subharmonic oscillation at high frequency operation of a power inverter |
| CN105720856A (en) * | 2016-04-22 | 2016-06-29 | 哈尔滨工业大学 | Capacitor voltage single sensor-based LCL-type gird-connected inverter control method |
-
2003
- 2003-10-24 CN CN 200320117330 patent/CN2655488Y/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100369344C (en) * | 2003-10-24 | 2008-02-13 | 华南理工大学 | Synthetized compensation device in electric power system and synthetized compensation method |
| CN100362739C (en) * | 2005-09-30 | 2008-01-16 | 武汉大学 | Method and device for producing electric motor arbitrary mechanical characteristic based on PWM technique |
| CN101212140B (en) * | 2006-12-29 | 2010-12-29 | 鸿富锦精密工业（深圳）有限公司 | Automatic power factor compensator |
| CN101252337B (en) * | 2007-02-20 | 2013-04-24 | 通用汽车环球科技运作公司 | Reduction of subharmonic oscillation at high frequency operation of a power inverter |
| CN102082442A (en) * | 2011-03-14 | 2011-06-01 | 丹东欣泰电气股份有限公司 | High-voltage static var generator (SVG) without starting circuit and method for connecting SVG to power grid |
| CN105720856A (en) * | 2016-04-22 | 2016-06-29 | 哈尔滨工业大学 | Capacitor voltage single sensor-based LCL-type gird-connected inverter control method |
| CN105720856B (en) * | 2016-04-22 | 2018-08-28 | 哈尔滨工业大学 | LCL type control method of grid-connected inverter based on capacitance voltage single-sensor |
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| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20041110 Termination date: 20121024 |