CN102684204B - Cascading-type STATCOM DC side capacitor voltage balance control method - Google Patents
Cascading-type STATCOM DC side capacitor voltage balance control method Download PDFInfo
- Publication number
- CN102684204B CN102684204B CN201210127195.7A CN201210127195A CN102684204B CN 102684204 B CN102684204 B CN 102684204B CN 201210127195 A CN201210127195 A CN 201210127195A CN 102684204 B CN102684204 B CN 102684204B
- Authority
- CN
- China
- Prior art keywords
- statcom
- reference value
- capacitor voltage
- bridge
- special bridge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000003990 capacitor Substances 0.000 title claims abstract description 84
- 238000000034 method Methods 0.000 title claims abstract description 56
- 238000012937 correction Methods 0.000 claims description 15
- 238000005259 measurement Methods 0.000 claims description 9
- 230000010354 integration Effects 0.000 claims description 8
- 238000001208 nuclear magnetic resonance pulse sequence Methods 0.000 claims description 5
- 230000003068 static effect Effects 0.000 abstract description 3
- 230000001360 synchronised effect Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 15
- 238000011217 control strategy Methods 0.000 description 10
- 238000005516 engineering process Methods 0.000 description 4
- 230000001413 cellular effect Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000010363 phase shift Effects 0.000 description 2
- 230000009897 systematic effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Images
Classifications
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/10—Flexible AC transmission systems [FACTS]
Abstract
The invention relates to a cascading-type STATCOM (Static Synchronous Compensator) DC (Direct Current) side capacitor voltage balance control method. In the control method, the direct current control and the indirect current control are combined. The method comprises the following steps: generating an active current reference value; selecting a special bridge; generating an STATCOM output current reference value; carrying out indirect current control of the special bridge; and carrying out direct current control of a non-special bridge. The control method provided by the invention is used for controlling the cascading-type STATCOM DC side capacitor voltage balance. The method not only ensures the balance of a DC capacitor voltage between H bridges and improves the response speed of a control link and optimizes the system performance, but also does not require an additional hardware circuit and cannot ensure the hardware cost of a STATCOM device to be increased.
Description
Technical field
The present invention relates to solve tandem type STATCOM STATCOM (Static Synchronous Compensator, be called for short STATCOM) control problem of DC capacitor voltage balance, be specifically related to a kind of control method of tandem type STATCOM DC capacitor voltage balance.
Background technology
At present, STATCOM Reactive Power Control is divided into Direct Current Control and the large class of indirect current control two.Direct Current Control, adopts following-up type PWM control technology to carry out FEEDBACK CONTROL to the instantaneous value of current waveform, the directly generation of control command electric current.Indirect current control, is phase place and the amplitude that produces alternating voltage first-harmonic by controlling STATCOM inverter, indirectly controls the ac-side current of STATCOM.Because Direct Current Control method is the tracking control to current instantaneous value, in the situation that switching frequency can meet the demands, control system response speed is very fast.And indirect current control method is not very high to the requirement of switching frequency, the technology such as normal and multiplex, many level, the PWM control large capacity STATCOM of applying that combines, but the response time is longer.
Cascade H bridge type multi-electrical level STATCOM is formed by the cascade of multiple voltage-type H bridge inverter, and the DC side of each cascade inverter unit provides voltage support by capacitor.Because each DC bus capacitor device is relatively independent, if each unit power output loss and parameter unbalanced or each unit there are differences, will cause the imbalance of each unit DC capacitor voltage, thereby cause that STATCOM control performance declines, even cause DC bus capacitor overvoltage, threaten equipment safety operation.
In the cascade multi-level STATCOM of employing phase shift Carrier-based PWM mode, the balance control strategy of DC capacitor voltage mainly comprises employing additional firmware circuit and does not adopt the large class of additional firmware circuit control two.
Adopt the method for additional firmware circuit to have: by carrying out the equivalent loss of adjusting device at a DC bus capacitor device adjustable resistance in parallel, based on ac bus method of energy exchanging with adopt DC bus method of energy exchanging etc.Additional hardware circuit has increased the complexity of STATCOM circuit topological structure, has improved control difficulty, has reduced the reliability of device, has increased device excess loss and cost.
Do not adopt the strategy of additional firmware circuit control DC capacitor voltage balance to mainly contain: the independent control strategy of DC capacitor voltage, the DC capacitor voltage hierarchical control strategy based on power signal and the method control capacitance balance of voltage that adopts phase-splitting transient current to follow the tracks of, list of references [1]-[4].
[1]J.A.Barrena，L.Marroyo，M.A.Rodriguez，et?al.DC?Voltage?Balancing?for?PWMCascaded?H-Bridge?Converter?Based?STATCOM.IEEE?IECON，Nov.7-10，2006，Paris，France：1840-1845.
[2]J.A.Barrena，L.Marroyo，M.A.Rodriguez.Individual?Voltage?Balancing?Strategy?for?PWM?Cascaded?H-Bridge?Converter-Based?STATCOM.IEEE?Transactions?on?Industrial?Electronics，2008，55(1)：21-29.
[3] Zhao Ruibin, Qiu Yufeng, Jing Ping. the DC side voltage control method of a kind of cascade STATCOM. power electronics, 2009 (4): 18-22.
[4]LIU?Zhao，SHI?Yan-jun，DUAN?Shan-xu，et?al.The?Research?of?DC?Capacitance?Voltage?Balancing?Strategy?Based?on?Cascade?STATCOM?Using?Individual?Phase?Instantaneous?Current?Tracking.IEEE?6
th?International?Power?Electronics?and?Motion?Control?Conference-ECCE?Asia.May?17-20，2009，Wuhan，China：1136-1140.
Summary of the invention
The problem existing for prior art, the object of this invention is to provide a kind of comprehensive current control method, for the control of cascade multi-level STATCOM DC capacitor voltage balance.The method has not only guaranteed the balance of DC capacitor voltage between each H bridge, improved controlling unit response speed, optimized systematic function, also without additional firmware circuit, can not increase the hardware cost of STATCOM STATCOM device.
The object of the invention is to adopt following technical proposals to realize:
A kind of tandem type STATCOM DC capacitor voltage balance control method, its improvements are, described control method comprises that Direct Current Control and indirect current control combine;
Described method comprises the steps:
A, generation active current reference value;
B, select special bridge;
C, generation STATCOM output current reference value;
D, the control of special bridge indirect current;
E, non-special bridge Direct Current Control.
The preferred technical scheme of one provided by the invention is: described Direct Current Control comprises FEEDBACK CONTROL current waveform instantaneous value, the generation of control command electric current; Described indirect current control refers to the phase place and the amplitude that produce alternating voltage first-harmonic by controlling STATCOM STATCOM, indirectly controls the ac-side current of STATCOM STATCOM.
The provided by the invention second preferred technical scheme is: active current reference value generation unit is realized described steps A and generated active current reference value; Described active current reference value generation unit comprises adder I, multiplier I, subtracter I sum-product intergrator I;
Described steps A comprises the steps:
A, make the input variable of described active current reference value generation unit with N DC capacitor voltage measured value, be input in adder I and sue for peace by the output variable of meter meter, obtain and be worth;
B, described step a with value and the constant amount 1/N input variable as multiplier I, the output variable of described multiplier I is the mean value of N DC capacitor voltage;
C, described mean value and DC capacitor voltage reference value are input to subtracter I, and the output variable of described subtracter I is DC capacitor voltage error amount;
D, described DC capacitor voltage error amount are input to integrator I and carry out integration, and the result of integration gained is active current reference value.
The provided by the invention the 3rd preferred technical scheme is: special bridge selected cell is realized described step B and selected special bridge; Described special bridge selected cell comprises N subtracter and comparator I;
Described step B comprises the steps:
(1) input variable using N DC capacitor voltage measured value and capacitance voltage reference value as a described N subtracter, each described DC capacitor voltage measured value and described capacitance voltage reference value compare respectively, obtain N output variable of N subtracter, a described N output variable is N the DC capacitor voltage margin of error;
(2) described N the DC capacitor voltage margin of error is input in comparator I, the described DC capacitor voltage margin of error compares between two in comparator I obtains maximum DC capacitor voltage error amount, and the H bridge of described maximum DC capacitor voltage error amount is special bridge.
The provided by the invention the 4th preferred technical scheme is: STATCOM output current reference value generation unit is realized described step C and generated STATCOM output current reference value; Described STATCOM output current reference value generation unit comprises phase-locked loop, SIN function maker, cosine function maker, two multipliers and adder II;
Described step C comprises the steps:
I, input variable take low-pressure side line voltage measurement value as described STATCOM output current reference value generation unit, try to achieve the phase value of described low-pressure side line voltage measurement value through described phase-locked loop;
Ii, described phase value obtain respectively corresponding sine function and cosine function value after inputting respectively SIN function maker and cosine function maker;
The active current reference value that iii, described sine function and steps A are tried to achieve is as the input of a multiplier; Described cosine function value and given reactive current reference value, as the input of another multiplier, obtain two output variables;
Iv, the output variable of step I ii is input in adder II, the output valve of described adder II is STATCOM output current reference value.
The provided by the invention the 5th preferred technical scheme is: special bridge indirect current control unit is realized the control of the special bridge indirect current of described step D; Described special bridge indirect current control unit comprises two integrators, multiplier II, adder III, subtracter II and PWM modulator I;
Described step D comprises the steps:
1. the maximum DC capacitor voltage error amount obtaining using step B is as the input variable of an integrator, obtain special bridge voltage correction amplitude through integral element, together with the output variable sine function of described special bridge voltage correction amplitude and step I i in step C, input multiplier II, obtain the voltage correction value of special bridge;
2. after STATCOM output current reference value step C being obtained and output current measured value superpose in subtracter II, another integrator of input carries out integration, obtains special bridge voltage reference value;
3. the special bridge voltage reference value that 2. the special bridge voltage correction value 1. step being obtained and step obtain is input in adder III, the signal of output is as the input variable of PWM modulator, output pulse sequence, described pulse train is as the pulse triggering signal of device for power switching in special bridge.
The provided by the invention the 6th preferred technical scheme is: the non-special bridge Direct Current Control of described step e is realized in non-special bridge Direct Current Control unit; Described non-special bridge Direct Current Control unit comprises subtracter III, two integrators and PWM modulator II;
Described step e comprises:
After superposeing in subtracter III, the STATCOM output current reference value that step C is obtained and non-special bridge output current measured value input successively in two integrators, the signal of output is as the input variable of PWM modulator II, output pulse sequence, as the pulse triggering signal of device for power switching in all non-special bridge except special bridge.
The provided by the invention the 7th preferred technical scheme is: described method is special bridge and non-special bridge by the H bridge dividing elements of N cascade.
One provided by the invention more preferably technical scheme is: described special bridge refers to the H bridge that adopts the control of indirect current control method; Described non-special bridge refers to the H bridge that adopts the control of Direct Current Control method.
Compared with prior art, the beneficial effect that the present invention reaches is:
1, STATCOM DC capacitor voltage balance control method provided by the invention is introduced the concept of comprehensive Current Control, and Direct Current Control and indirect current control method, in conjunction with application, have been reduced to control difficulty, has improved the reliability of controlling.
2, STATCOM DC capacitor voltage balance control method provided by the invention is introduced the concept of special bridge and non-special bridge, sets different constraints choose special bridge according to actual requirement.
3, STATCOM DC capacitor voltage balance control method provided by the invention adopts respectively indirect current control and Direct Current Control to special bridge and non-special bridge, guarantees that DC capacitor voltage reaches balance between each H bridge.
4, STATCOM DC capacitor voltage balance control method provided by the invention adopts comprehensive current control method, guarantees that DC capacitor voltage reaches balance between each H bridge, and has very fast response speed, and STATCOM device performance is played to optimization function.
5, STATCOM DC capacitor voltage balance control method provided by the invention adopts comprehensive Current Control, without additional firmware circuit, can not increase the hardware cost of STATCOM device, and has simplified STATCOM circuit topological structure.
6, STATCOM DC capacitor voltage balance control method clear thinking provided by the invention, controls and is easy to realize.
Accompanying drawing explanation
Fig. 1 is the flow chart of STATCOM DC capacitor voltage balance control method provided by the invention;
Fig. 2 is single-phase Cascade H bridge multi-level STATCOM topology diagram;
Fig. 3 is H bridge unit topology diagram;
Fig. 4 is the schematic diagram of STATCOM DC capacitor voltage balance control circuit provided by the invention;
Fig. 5 is the structure chart that active current reference value of the present invention generates link unit;
Fig. 6 is the control block diagram that active current reference value of the present invention generates link;
Fig. 7 is the structure chart of special bridge selected cell of the present invention;
Fig. 8 is that special bridge of the present invention is selected control block diagram;
Fig. 9 is the structure chart that STATCOM output current reference value of the present invention generates link unit;
Figure 10 is the control block diagram that STATCOM output current reference value of the present invention generates link;
Figure 11 is special bridge indirect current control unit structure chart of the present invention;
Figure 12 is the control block diagram of the special bridge of employing indirect current control method control of the present invention;
Figure 13 is non-special bridge Direct Current Control cellular construction figure of the present invention;
Figure 14 is the control block diagram of the non-special bridge of employing Direct Current Control method control of the present invention;
Figure 15 is 5 H bridge cascade model DC capacitor voltage oscillograms.
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.
STATCOM DC capacitor voltage balance control method provided by the invention is used for solving tandem type STATCOM (Static Synchronous Compensator, be called for short STATCOM) control problem of DC capacitor voltage balance, also can be used for solving the voltage balance control problem of other power electronic equipments based on cascade multilevel inverter technology.
H bridge multi-level STATCOM comprises three-phase six brachium pontis, and every is Cascade H bridge mutually.As shown in Figure 2, Fig. 2 is single-phase Cascade H bridge multi-level STATCOM topology diagram, and every phase Cascade H bridge comprises H bridge unit, a N DC bus capacitor C of high voltage bus, low-voltage bus bar, single-phase transformer T, reactor L, resistance R s, a N cascade
1-C
nand corresponding voltage measurement table meter V
1-V
n, low-pressure side line current meter meter i
abwith low-pressure side line voltage measurement table meter u
aB.
The secondary side of single-phase transformer T, low-pressure side line voltage measurement table meter u
aB, reactor L, resistance R s, low-pressure side line current meter meter i
abbe connected successively with the H bridge unit of N cascade; Its corresponding meter meter parallel connection of each H bridge unit.
Wherein the topological structure of each H bridge unit as shown in Figure 3, comprises 2 couples of device for power switching P
1-P
4, 2 couples of anti-paralleled diode D
1-D
4with 1 DC bus capacitor.
Fig. 4 is the schematic diagram of STATCOM DC capacitor voltage balance control circuit provided by the invention, STATCOM DC capacitor voltage balance control method provided by the invention is to adopt control circuit to realize, and control circuit comprises the active current reference value generation unit, generation STATCOM output current reference value generation unit, special bridge selected cell, special bridge indirect current control unit and the non-special Direct Current Control unit that connect successively.
As shown in Figure 1, Fig. 1 is the flow chart of STATCOM DC capacitor voltage balance control method provided by the invention, and STATCOM DC capacitor voltage balance control method provided by the invention comprises following implementation step:
1, generate active current reference value.
Generating active current reference value is realized by active current reference value generation unit.As shown in Figure 5, Fig. 5 is the structure chart that active current reference value of the present invention generates link unit, and active current reference value generation unit comprises adder I, multiplier I, subtracter I sum-product intergrator I; Adder I, multiplier I, subtracter I sum-product intergrator I connect successively.
In DC side meter Table V
1-V
noutput variable u
dc1-u
dcNfor the input variable of adder, N DC capacitor voltage measured value is input, utilizes adder, multiplier, subtracter sum-product intergrator to realize.By u
dc1-u
dcNinput summer summation, obtains and is worth; With value and the constant amount 1/N input as multiplier, acquired results is the mean value of N DC capacitor voltage; This mean value again with given capacitance voltage reference value
input together subtracter, the error amount input integral device obtaining in subtracter carries out integration, and acquired results is active current reference value
As shown in Figure 6, Fig. 6 is the control block diagram that active current reference value of the present invention generates link, and in figure, hypothesis has the cascade of N H bridge,
for DC capacitor voltage reference value,
for N H bridge capacitance voltage mean value, u
dcj, be j H bridge capacitance voltage value, U
mfor line voltage U
aBamplitude,
for active current reference value, T
f, k
u, τ
ufor controlling unit parameter.By the N measuring a H bridge DC capacitor voltage input control link, try to achieve after mean value with reference value relatively error amount.After the controlling unit of this error amount by design, obtain active current reference value.Obtain active current reference value by error amount, also can realize by other control strategy, be not limited only to scheme shown in Fig. 6 dotted line frame.
2, special bridge is selected.
Special bridge is selected to be realized by special bridge selected cell.As shown in Figure 7, Fig. 7 is the structure chart of special bridge selected cell of the present invention, and special bridge selected cell comprises N subtracter and 1 multi-input comparator, N subtracter and 1 multi-input comparator I series connection.
Active current reference value is identical with generating, with N DC capacitor voltage measured value u
dc1-u
dcNas the input variable of N subtracter, then to each subtracter input capacitance voltage reference value
compare respectively, obtain N voltage error amount.This N voltage error amount is input in the multi-input comparator of next stage, compares between two and obtains maximum voltage error amount Δ u
dck, subscript k represents to occur the H bridge numbering of maximum voltage error, is special bridge.
As shown in Figure 8, Fig. 8 is the control block diagram of choosing special bridge according to the maximum principle of the absolute value of DC capacitor voltage and its reference value error, the H bridge that adopts indirect current control method is defined as special bridge by the present invention, because the H bridge quantity controlling by the method is relatively less, non-special bridge is occupied an leading position.In figure,
for DC capacitor voltage reference value, u
dcjbe j H bridge capacitance voltage value, Δ u
dcjbe j H bridge capacitance voltage value error amount.Each voltage error value is input in maximizing link max after asking absolute value link abs, obtains Δ u
dck, show that k H bridge capacitance voltage departs from reference value maximum, need to carry out capacitance voltage correction to it.The selection of special bridge, not only can choose according to the maximum principle of the absolute value of DC capacitor voltage shown in Fig. 8 and its reference value error, two (or other quantity of setting) H bridges, the Error Absolute Value that also alternative condition can be set as to Error Absolute Value maximum are greater than multiple H bridges of the threshold value of setting, from two (or other quantity of setting) H bridges of positive and negative both direction error amount maximum etc.
3, generate STATCOM output current reference value.
Generating STATCOM output current reference value is realized by STATCOM output current reference value generation unit.As shown in Figure 9, STATCOM output current reference value generation unit comprises phase-locked loop, SIN function maker, cosine function maker, 2 multipliers and adder II; Phase-locked loop, function maker, multiplier and adder II are connected successively.
With low-pressure side line voltage measurement value u
aBfor the unique input variable of STATCOM output current reference value generation unit, try to achieve u through phase-locked loop
aBphase value θ.θ inputs respectively SIN function maker and cosine function maker, obtains corresponding sine, cosine function value sin θ and cos θ.Now, the active current reference value that sin θ and step 1 are tried to achieve
as the input of 1 multiplier, cos θ and given reactive current reference value
as the input of other 1 multiplier, 2 output variables that the output of two multipliers obtains are again in input summer, and the output of adder obtains and is worth, and itself and value are exactly STATCOM output current reference value
As shown in figure 10, Figure 10 is the control block diagram that STATCOM output current reference value of the present invention generates link, in figure, and U
aBfor line voltage,
for active current reference value,
for reactive current reference value,
for STATCOM output current reference value.Sin θ is and line voltage U
aBsynchronous sinusoidal component.
4, special bridge indirect current control.
The control of special bridge indirect current is realized by special bridge indirect current control unit.As shown in figure 11, Figure 11 is special bridge indirect current control unit structure chart of the present invention, special bridge indirect current control unit PWM modulator I, adder III, subtracter II, multiplier IV, integrator II sum-product intergrator III; Described subtracter II and integrator III connect to form subtracter II and integrator III branch road; Described multiplier IV and integrator II connect to form multiplier IV and integrator II branch road; Described adder III is connected with integrator II branch road with integrator III branch road and multiplier IV with subtracter II respectively; Described PWM modulator I is connected with adder III;
The maximum voltage error amount Δ u obtaining with step 2
dckas the input variable of an integrator, obtain the amplitude u of k H bridge (being special bridge) voltage increment through integral element
abk, u
abktogether with the middle output variable sin θ trying to achieve with step 3 again, input multiplier, obtain the voltage correction value of special bridge.Meanwhile, output current reference value step 3 being obtained and output current measured value i
abin subtracter II, after stack, another integrator of input carries out integration, obtains special bridge voltage reference value
by voltage reference value
superpose in adder with voltage correction value, the signal of output is as the input variable of PWM modulator, output pulse sequence, and described pulse train is as the pulse triggering signal of device for power switching in special bridge.
As shown in figure 12, Figure 12 is the control block diagram of the special bridge of employing indirect current control method control of the present invention.Adopt indirect current control method to revise k H bridge (special bridge) capacitance voltage.In figure,
for STATCOM output current reference value, i
abfor output current measured value,
it is the H bridge output voltage reference value being generated by control strategy.Generate
control strategy also can realize by other control strategy, be not limited only to scheme shown in Figure 12 dotted line frame.
for DC capacitor voltage reference value, u
dckbe k H bridge capacitance voltage value, Δ u
dckbe k H bridge capacitance voltage value error amount.Δ u
dckafter PID controlling unit as shown in dotted outline in FIG., obtain the amplitude u of voltage increment
abk, multiplying each other and obtaining k H bridge output voltage correction value with sin θ.K
1-k
4, τ
1-τ
4it is the parameter of controlling unit.Sin θ is and line voltage U
aBsynchronous sinusoidal component, the middle output variable of Figure 10 controlling unit.Generate u
abkcontrol strategy also can realize by other control strategy, be not limited only to scheme shown in Figure 12 dotted line frame.
5, non-special bridge Direct Current Control.
Non-special bridge Direct Current Control is realized by non-special bridge Direct Current Control unit.As shown in figure 13, Figure 13 is non-special bridge Direct Current Control cellular construction figure of the present invention, and non-special bridge Direct Current Control unit comprises subtracter, 2 integrators and PWM modulator II; Subtracter, 2 integrators are connected successively with PWM modulator II.
Due to the DC capacitor voltage error amount of non-special bridge within the acceptable range, therefore do not need to carry out voltage correction, and take direct current control can obtain control response speed faster.The STATCOM output current reference value that the 3rd step is obtained
with output current measured value i
abin adder, after stack, input successively in 2 integrators, gained signal, as the input variable of phase-shift PWM modulator, is finally exported set of pulses sequence, as the start pulse signal of device for power switching in all non-special bridge except k H bridge.
As shown in figure 14, Figure 14 is the control block diagram of the non-special bridge of employing Direct Current Control method control of the present invention.Select after special bridge, other H bridge can be referred to as non-special bridge.
for STATCOM output current reference value, i.e. the output variable of Figure 12 controlling unit, i
abfor STATCOM output current measured value, k
p, k
ifor PI link parameter, τ
1and τ
2it is lead and lag controlling unit parameter.
with i
aberror amount after PI link and lead and lag correction link, obtain command signal i
cmd.I
cmdwith the dephased one group of carrier signal of tool relatively after, export the trigger impulse of non-special bridge
(j=1 ..., k-1, k+1 ..., N).Controlling unit in figure in dotted line frame also can realize with other control strategies.
Adopt after above-mentioned control implementation, in the example of calculation shows that is provided with the cascade of 5 H bridges, verify.Figure 15 has provided and has dropped into before and after the designed capacitance voltage balance control circuit of the present invention, each H bridge capacitance voltage oscillogram.In the time of 0.45s, drop into the control of capacitance voltage balance, wherein long lines U
dcfor the mean value of capacitance voltage.Can find out, while not dropping into the control of capacitance voltage balance, capacitance voltage and the mean value of unit differ greatly, and take unit I as example, maximum deviation can reach about 220V, and pass in time increase tendency in addition; After having added the control of capacitance voltage balance, the capacitance voltage curves of unit almost overlaps with mean value, and maximum deviation is no more than 5V.
STATCOM DC capacitor voltage balance control method provided by the invention has not only guaranteed the balance of DC capacitor voltage between each H bridge, improved controlling unit response speed, optimized systematic function, also without additional firmware circuit, can not increase the hardware cost of STATCOM device.
Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although the present invention is had been described in detail with reference to above-described embodiment, those of ordinary skill in the field are to be understood that: still can modify or be equal to replacement the specific embodiment of the present invention, and do not depart from any modification of spirit and scope of the invention or be equal to replacement, it all should be encompassed in the middle of claim scope of the present invention.
Claims (8)
1. a tandem type STATCOM DC capacitor voltage balance control method, is characterized in that, described control method comprises that Direct Current Control and indirect current control combine;
Described method comprises the steps:
A, generation active current reference value;
B, select special bridge;
C, generation STATCOM output current reference value;
D, the control of special bridge indirect current;
E, non-special bridge Direct Current Control;
Special bridge selected cell is realized described step B and is selected special bridge; Described special bridge selected cell comprises N subtracter and comparator I;
Described step B comprises the steps:
(1) input variable using N DC capacitor voltage measured value and capacitance voltage reference value as a described N subtracter, each described DC capacitor voltage measured value and described capacitance voltage reference value compare respectively, obtain N output variable of N subtracter, a described N output variable is N the DC capacitor voltage margin of error;
(2) described N the DC capacitor voltage margin of error is input in comparator I, the described DC capacitor voltage margin of error compares between two in comparator I obtains maximum DC capacitor voltage error amount, and the H bridge of described maximum DC capacitor voltage error amount is special bridge.
2. STATCOM DC capacitor voltage balance control method as claimed in claim 1, is characterized in that, described Direct Current Control comprises FEEDBACK CONTROL current waveform instantaneous value, the generation of control command electric current; Described indirect current control refers to the phase place and the amplitude that produce alternating voltage first-harmonic by controlling STATCOM STATCOM, indirectly controls the ac-side current of STATCOM STATCOM.
3. STATCOM DC capacitor voltage balance control method as claimed in claim 1, is characterized in that, active current reference value generation unit is realized described steps A and generated active current reference value; Described active current reference value generation unit comprises adder I, multiplier I, subtracter I sum-product intergrator I;
Described steps A comprises the steps:
A, make the input variable of described active current reference value generation unit with N DC capacitor voltage measured value, be input in adder I and sue for peace by the output variable of meter meter, obtain and be worth;
B, described step a with value and the constant amount 1/N input variable as multiplier I, the output variable of described multiplier I is the mean value of N DC capacitor voltage;
C, described mean value and DC capacitor voltage reference value are input to subtracter I, and the output variable of described subtracter I is DC capacitor voltage error amount;
D, described DC capacitor voltage error amount are input to integrator I and carry out integration, and the result of integration gained is active current reference value.
4. STATCOM DC capacitor voltage balance control method as claimed in claim 1, is characterized in that, STATCOM output current reference value generation unit is realized described step C and generated STATCOM output current reference value; Described STATCOM output current reference value generation unit comprises phase-locked loop, SIN function maker, cosine function maker, two multipliers and adder II;
Described step C comprises the steps:
I, input variable take low-pressure side line voltage measurement value as described STATCOM output current reference value generation unit, try to achieve the phase value of described low-pressure side line voltage measurement value through described phase-locked loop;
II, described phase value obtain respectively sine function and cosine function value after inputting respectively SIN function maker and cosine function maker;
The active current reference value that III, described sine function and steps A are tried to achieve is as the input of a multiplier; Described cosine function value and given reactive current reference value, as the input of another multiplier, obtain two output variables;
IV, the output variable of step III is input in adder II, the output valve of described adder II is STATCOM output current reference value.
5. STATCOM DC capacitor voltage balance control method as claimed in claim 1, is characterized in that, special bridge indirect current control unit is realized the control of the special bridge indirect current of described step D; Described special bridge indirect current control unit comprises two integrators, multiplier II, adder III, subtracter II and PWM modulator I;
Described step D comprises the steps:
1. the maximum DC capacitor voltage error amount obtaining using step B is as the input variable of an integrator, obtain special bridge voltage correction amplitude through integral element, together with the output variable sine function of described special bridge voltage correction amplitude and step II in step C, input multiplier II, obtain special bridge voltage correction value;
2. after STATCOM output current reference value input and output current measurement value step C being obtained superposes in subtracter II, another integrator carries out integration, obtains special bridge voltage reference value;
3. the special bridge voltage reference value that 2. the special bridge voltage correction value 1. step being obtained and step obtain is input in adder III, the signal of output is as the input variable of PWM modulator, output pulse sequence, described pulse train is as the pulse triggering signal of device for power switching in special bridge.
6. STATCOM DC capacitor voltage balance control method as claimed in claim 1, is characterized in that, the non-special bridge Direct Current Control of described step e is realized in non-special bridge Direct Current Control unit; Described non-special bridge Direct Current Control unit comprises subtracter III, two integrators and PWM modulator II;
Described step e comprises:
After superposeing in subtracter III, the STATCOM output current reference value that step C is obtained and non-special bridge output current measured value input successively in two integrators, the signal of output is as the input variable of PWM modulator II, output pulse sequence, described pulse train is as the pulse triggering signal of device for power switching in all non-special bridge except special bridge.
7. STATCOM DC capacitor voltage balance control method as claimed in claim 1, is characterized in that, described method is special bridge and non-special bridge by the H bridge dividing elements of N cascade.
8. STATCOM DC capacitor voltage balance control method as claimed in claim 7, is characterized in that, described special bridge refers to the H bridge that adopts the control of indirect current control method; Described non-special bridge refers to the H bridge that adopts the control of Direct Current Control method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210127195.7A CN102684204B (en) | 2012-04-26 | 2012-04-26 | Cascading-type STATCOM DC side capacitor voltage balance control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210127195.7A CN102684204B (en) | 2012-04-26 | 2012-04-26 | Cascading-type STATCOM DC side capacitor voltage balance control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102684204A CN102684204A (en) | 2012-09-19 |
| CN102684204B true CN102684204B (en) | 2014-05-21 |
Family
ID=46815744
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210127195.7A Active CN102684204B (en) | 2012-04-26 | 2012-04-26 | Cascading-type STATCOM DC side capacitor voltage balance control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102684204B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9941813B2 (en) | 2013-03-14 | 2018-04-10 | Solaredge Technologies Ltd. | High frequency multi-level inverter |
| US9318974B2 (en) | 2014-03-26 | 2016-04-19 | Solaredge Technologies Ltd. | Multi-level inverter with flying capacitor topology |
| CN103956915B (en) * | 2014-05-12 | 2016-08-31 | 东南大学 | Cascaded H-bridges changer master-slave control method based on current coupling |
| CN104505844B (en) * | 2015-01-08 | 2017-01-11 | 国网上海市电力公司 | Cascaded STATCOM capacitor voltage balance control method based on active voltage vector reduplication |
| CN105322554A (en) * | 2015-11-25 | 2016-02-10 | 中国船舶重工集团公司第七二二研究所 | Prediction method for capacitor voltage fluctuation in direct current side of chain type STATCOM (static synchronous compensator) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101001053A (en) * | 2006-01-10 | 2007-07-18 | 北京信息工程学院 | Energy controlling tractics of three-phase voltage-type PWM rectifier |
| CN101719730A (en) * | 2009-12-08 | 2010-06-02 | 中国北车股份有限公司大连电力牵引研发中心 | Current controlling method of three-phase four-quadrant rectifier |
| CN202142865U (en) * | 2011-07-12 | 2012-02-08 | 辽宁省电力有限公司朝阳供电公司 | Multifunctional SVG cooperated FC control circuit |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002247760A (en) * | 2001-02-15 | 2002-08-30 | Toshiba Corp | Starting method of serial compensator |
| JP4673174B2 (en) * | 2005-09-22 | 2011-04-20 | 東芝三菱電機産業システム株式会社 | Semiconductor switch control device |
-
2012
- 2012-04-26 CN CN201210127195.7A patent/CN102684204B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101001053A (en) * | 2006-01-10 | 2007-07-18 | 北京信息工程学院 | Energy controlling tractics of three-phase voltage-type PWM rectifier |
| CN101719730A (en) * | 2009-12-08 | 2010-06-02 | 中国北车股份有限公司大连电力牵引研发中心 | Current controlling method of three-phase four-quadrant rectifier |
| CN202142865U (en) * | 2011-07-12 | 2012-02-08 | 辽宁省电力有限公司朝阳供电公司 | Multifunctional SVG cooperated FC control circuit |
Non-Patent Citations (2)
| Title |
|---|
| JP特开2002-247760A 2002.08.30 |
| JP特开2007-87154A 2007.04.05 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102684204A (en) | 2012-09-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102832841B (en) | Modularized multi-level converter with auxiliary diode | |
| CN103197241B (en) | Flexible DC power transmission MMC converter valve operating test device and test method | |
| CN106100402B (en) | A kind of T-type three-level inverter and its neutral balance control method | |
| Li et al. | New technologies of modular multilevel converter for VSC-HVDC application | |
| CN104934989A (en) | Reactive power compensation device based on novel modular multilevel topology and control method thereof | |
| CN107046375B (en) | A kind of MMC circular current control method of bridge arm single-sensor | |
| CN103683288A (en) | Parallel active filter based on modularization multi-level converter and control method of parallel active filter | |
| CN105071403B (en) | Reactive power compensator and control method based on dual H-bridge modular multilevel topology | |
| CN104836424A (en) | Energy router with cascaded module voltage automatic balancing circuit | |
| CN102684204B (en) | Cascading-type STATCOM DC side capacitor voltage balance control method | |
| CN101950960B (en) | Control method of DC bus voltage of cascading multi-level power quality conditioners | |
| CN108233394A (en) | A kind of capacitive coupling voltage balancing control method suitable for Y type chain types STATCOM | |
| CN108879715B (en) | Voltage control method based on cascade U-Cell topology static synchronous compensator | |
| CN104917190A (en) | Decentralized control method for H-bridge cascaded power grid static reactive power compensator | |
| Cheng et al. | A novel unidirectional three-phase multilevel rectifier composed of star-connected three single-phase topology based on five-level flying capacitor DC–DC converter | |
| Jin et al. | Nine-level she-pwm vsc based statcom for var compensation | |
| CN204858577U (en) | Reactive power compensator based on two many level of H bridge modularization transverters | |
| Gangui et al. | Research on modular multilevel converter suitable for direct-drive wind power system | |
| CN102931864B (en) | Method for voltage balance control of DC (direct current) buses of power units of cascade static var generator | |
| CN202772582U (en) | Cascade STATCOM DC side capacitor voltage balance control circuit | |
| CN103929072B (en) | A kind of control method of AC-DC series resonance matrix converter | |
| CN102664549B (en) | Cascade inverter voltage balance and control method based on power device on-off distribution | |
| CN204992594U (en) | Reactive power compensator based on novel many level of modularization topological structure | |
| CN111952995B (en) | Direct-current capacitor voltage balance control method under single-phase fault of power grid | |
| CN102694385A (en) | Phase current balancing and amplitude-limiting method for asymmetrical compensation of line current of distribution static compensator (D-STATCOM) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| ASS | Succession or assignment of patent right |
Owner name: INSTITUTE OF STATE GRID INTELLIGENT ELECTRIC GRIDS Effective date: 20140217 Owner name: STATE GRID CORPORATION OF CHINA Free format text: FORMER OWNER: CHINA ELECTRIC PRIME TECHNOLOGY CO., LTD. Effective date: 20140217 |
|
| COR | Change of bibliographic data |
Free format text: CORRECT: ADDRESS; FROM: 102200 CHANGPING, BEIJING TO: 100031 XICHENG, BEIJING |
|
| TA01 | Transfer of patent application right |
Effective date of registration: 20140217 Address after: 100031 Xicheng District West Chang'an Avenue, No. 86, Beijing Applicant after: State Grid Corporation of China Applicant after: STATE GRID SMART GRID Research Institute Applicant after: CHINA EPRI SCIENCE & TECHNOLOGY Co.,Ltd. Address before: 102200 Beijing city Changping District South Shao Zhen Nan Road No. 16 Applicant before: CHINA EPRI SCIENCE & TECHNOLOGY Co.,Ltd. |
|
| TA01 | Transfer of patent application right | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 100031 Xicheng District West Chang'an Avenue, No. 86, Beijing Co-patentee after: GLOBAL ENERGY INTERCONNECTION Research Institute Patentee after: State Grid Corporation of China Co-patentee after: CHINA EPRI SCIENCE & TECHNOLOGY Co.,Ltd. Address before: 100031 Xicheng District West Chang'an Avenue, No. 86, Beijing Co-patentee before: STATE GRID SMART GRID Research Institute Patentee before: State Grid Corporation of China Co-patentee before: CHINA EPRI SCIENCE & TECHNOLOGY Co.,Ltd. |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20170612 Address after: 100031 Xicheng District West Chang'an Avenue, No. 86, Beijing Co-patentee after: GLOBAL ENERGY INTERCONNECTION Research Institute Patentee after: State Grid Corporation of China Address before: 100031 Xicheng District West Chang'an Avenue, No. 86, Beijing Co-patentee before: GLOBAL ENERGY INTERCONNECTION Research Institute Patentee before: State Grid Corporation of China Co-patentee before: CHINA EPRI SCIENCE & TECHNOLOGY Co.,Ltd. |