CN113422369A - Optimized operation and control method of fault flexible arc extinction and power quality regulation and control composite system - Google Patents

Optimized operation and control method of fault flexible arc extinction and power quality regulation and control composite system Download PDF

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CN113422369A
CN113422369A CN202110867066.0A CN202110867066A CN113422369A CN 113422369 A CN113422369 A CN 113422369A CN 202110867066 A CN202110867066 A CN 202110867066A CN 113422369 A CN113422369 A CN 113422369A
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tclc
fault
grid
inductance
capacitor
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CN113422369B (en
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郭祺
涂春鸣
黄泽钧
肖凡
姜飞
肖泽坤
卢柏桦
高家元
兰征
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Hunan University
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
    • H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
    • H02J3/1842—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
    • H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
    • H02J3/1864—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein the stepless control of reactive power is obtained by at least one reactive element connected in series with a semiconductor switch
    • 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
    • Y02E40/30—Reactive power compensation

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Abstract

The invention discloses an optimized operation and control method of a fault flexible arc extinction and power quality regulation and control composite system1And VT2The trigger angle of (a) is 180 DEG, so that the TCLC structure presents the capacitance, and the capacitance reactance and the capacitance C of the TCLC structure are set1The TCLC structure compensates all reactive power; when the single-phase earth fault occurs in the power grid, the thyristor VT is controlled1And VT2The trigger angle of (a) is 90 DEG, the TCLC structure is inductive, and the reactance and inductance L of the TCLC structure are set1And an inductance L2The TCLC structure injects a maximum inductive crowbar current. The capacitor voltage at the direct current side of the MF-GCI is effectively reduced, and the safe operation of the MF-GCI is ensured.

Description

Optimized operation and control method of fault flexible arc extinction and power quality regulation and control composite system
Technical Field
The invention belongs to the technical field of arc extinction of power distribution networks, and particularly relates to an optimized operation and control method of a fault flexible arc extinction and power quality regulation and control composite system.
Background
The distribution network equipment is complicated, the users are numerous, the coverage area is wide, the geographic conditions are various, the distribution network equipment is influenced by external conditions such as user capacity increase and the like and factors such as city construction, and the probability of failure is relatively high. When the single-phase earth fault occurs in the power distribution network, the non-fault phase-to-earth voltage rises, and system overvoltage can be caused, so that insulation breakdown is caused, and the phase-to-phase short circuit is easily expanded.
As a bridge for connecting a power transmission system and a power consumer, the safe operation of the power distribution network directly relates to the benefit of the consumer, so that the ground fault current of the power distribution network is restrained in time after a single-phase ground fault occurs, and the power distribution network can operate reliably. The existing arc extinction technology is divided into passive arc extinction and active arc extinction, and a passive arc extinction device mainly comprises a fixed compensation type arc extinction coil and an automatic tuning type arc extinction coil; because the passive arc suppression device only contains passive elements, only the reactive component in the fault current can be compensated. With the development of power electronic technology, in order to further improve the compensation effect of single-phase earth fault current, active arc extinction is provided, full compensation current is injected into a power distribution network system through an inverter circuit formed by power electronic devices in the active arc extinction technology, not only can reactive components in the fault current be compensated, but also active and harmonic components can be compensated, and therefore the purpose of effectively suppressing arc current is achieved. At present, the domestic power distribution network active arc extinction technologies mainly comprise the following technologies: an active arc suppression coil method based on a master-slave converter, an active arc suppression method based on flexible grounding control, a fault arc suppression method based on a cascaded H-bridge converter and the like. An existing grid-connected inverter (MF-GCI) with single-phase ground fault regulation and reactive compensation capability is composed of an active current converting part and a passive part, wherein the active current converting part of the active current converting part adopts an active inverter circuit, the passive part adopts a Static Var Compensator (SVC) or a magnetic valve type controllable reactor (MCR) and other devices, and the passive part can compensate a fault current reactive component and continuously and smoothly regulate a reactance, so that the capacity of the active part is reduced; the active part can compensate the active component and harmonic component of the fault current, and the performance of the passive structure is improved; the active part and the passive part are coordinated and matched to realize function complementation and integral capacity optimization. However, in the scheme, the function realization under the two modes of reactive compensation and fault arc extinction and the reasonable capacity distribution of the active and passive parts need to be comprehensively considered, and the related factors are multiple and complex. In addition, when the MF-GCI is switched in different modes, the problems of transient voltage and current impact are very likely to be generated due to the dynamic adjustment of the reactance characteristics of active and passive parts, and the operation safety of the active part and even the whole MF-GCI is seriously threatened.
Disclosure of Invention
The embodiment of the invention aims to provide an optimized operation and control method of a fault flexible arc extinction and power quality regulation composite system, which solves the problems of complex design of MF-GCI and transient voltage and current impact generated during mode switching; and the problem that the active part and the passive part are matched with each other when different modes are switched.
In order to solve the technical problems, the technical scheme adopted by the invention is an optimized operation and control method of a fault flexible arc extinction and power quality regulation composite system, wherein the fault flexible arc extinction and power quality regulation composite system comprises a grid-connected converter, and the grid-connected converter is formed by connecting an active current transformation part, an active current transformation part and a passive part in series;
the passive part is a TCLC structure, and the reactor and the capacitor C are controlled by a thyristor controlled by the thyristor1And a filter inductance L2The thyristor-controlled reactor is formed by a thyristor VT1、VT2And an inductance L1Composition, thyristor VT1And VT2Inverse parallel connection, inductance L1And thyristor VT1And VT2Formed as a whole in series, a capacitor C1Parallel connected with thyristor controlled reactor, filter inductance L2One end of the reactor is connected in series with a thyristor controlled reactor and a capacitor C1On the node of (2); filter inductance L2The other end is connected in series with an active current transformation part of the active current transformation part;
the method comprises controlling thyristor VT when the power grid is in normal operation1And VT2The trigger angle of (a) is 180 DEG, so that the TCLC structure presents the capacitance, and the capacitance reactance and the capacitance C of the TCLC structure are set1The TCLC structure compensates all reactive power;
when the single-phase earth fault occurs in the power grid, the thyristor VT is controlled1And VT2The trigger angle of (a) is 90, so that the TCLC structure is inductive, and the reactance and the inductance L of the TCLC structure are set1And an inductance L2The TCLC structure injects a maximum inductive crowbar current.
Further, the reactance of the TCLC structure during normal operation of the power grid is:
Figure BDA0003187804570000021
wherein, VsxThe grid side voltage, x ═ a, b, c; qTCLC(max)The maximum reactive power injected into the power grid from the grid-connected converter;
Figure BDA0003187804570000022
is an inductance L2A reactance of (d);
Figure BDA0003187804570000023
is a capacitor C1The reactance of (c).
Further, the capacitor C1When the power grid normally operates, the method comprises the following steps:
Figure BDA0003187804570000024
wherein E isxIs the grid voltage; l is2Is a filter inductor L2The inductance and omega are fundamental angular frequency; (ii) a QTCLC(max)Is the maximum reactive power injected into the grid from the grid-connected converter.
Further, the maximum reactive power injected into the power grid from the grid-connected converter is greater than or equal to the reactive power required to be compensated by the load.
Furthermore, the grid-connected converter is locked for a period when the power grid has a single-phase earth fault, and then the thyristor VT is controlled1And VT2The trigger angle between the two is alpha-90 degrees, the thyristor is fully conducted and is equivalently inductance L1Capacitor C1In parallel connection, the current flowing through the thyristor controlled reactor is larger than the capacitor C1The current flowing therethrough.
Further, the reactance of the TCLC structure when a single-phase ground fault occurs in the power grid is:
Figure BDA0003187804570000031
wherein, Im(max)The maximum arc extinction active current is injected for the non-fault phase MF-GCI; i isR(max)The maximum arc-extinguishing reactive current is injected for the non-fault phase MF-GCI;
Figure BDA0003187804570000032
is an inductance L1A reactance of (d);
Figure BDA0003187804570000033
is a capacitor C1A reactance of (d);
Figure BDA0003187804570000034
is an inductance L2A reactance of (d); and is
Figure BDA0003187804570000035
Wherein: r isxIs a non-fault phase line resistance to ground, C0xThe non-fault phase line is a ground capacitor; (ii) a ExIs the supply voltage.
Further, setting an inductance L of the TCLC structure1The inductance of (a) is:
Figure BDA0003187804570000036
wherein, C1A capacitance that is a TCLC structure;
L2is an inductance L2For reducing current ripple of the MF-GCI output, and
Figure BDA0003187804570000037
wherein, VdcxIs the DC side capacitor voltage, fsFor switching frequency, Δ icxmaxThe current is injected for the maximum ripple allowed by the MF-GCI.
Further, when the grid has a single-phase earth fault, the grid-connected converter is locked as follows: switching on an upper bridge arm of an active current converting part of the active current converting part and switching off a lower bridge arm of the active current converting part; or closing the upper bridge arm of the active current converting part and simultaneously conducting the lower bridge arm of the active current converting part;
the active current converting part consists of a pulse width modulation converter and a direct current side energy storage capacitor, and the direct current side energy storage capacitor is connected to the direct current side of the pulse width modulation converter; the pulse width modulation converter is composed of 4 full-control device insulated gate bipolar transistors IGBT1, IGBT2, IGBT3, IGBT4 and 4 freewheeling diodes, the IGBT and the freewheeling diodes are connected in an anti-parallel mode, the positive electrode of a direct-current side energy storage capacitor is connected with the collector electrode of the IGBT1, and the node emitter of the direct-current side energy storage capacitor negative electrode IGBT3 is connected. Active current converting part one end of the active current converting part is connected in series to the passive part through the node of the emitter of the IGBT2 and the collector of the IGBT4, and the other end is grounded through the node of the emitter of the IGBT1 and the collector of the IGBT 3.
The invention has the beneficial effects that: by theoretical analysis and research on the operation characteristics of the MF-GCI, the problems of complex parameter design of the MF-GCI and transient voltage and current impact generated during mode switching are solved, the capacitor voltage on the DC side of the MF-GCI is effectively reduced, and the safe operation of the MF-GCI is ensured.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a circuit topology diagram of a fault flexible arc extinction and power quality control composite system according to an embodiment of the invention;
FIG. 2 is an MF-GCI operating waveform without the inter-mode flexible switching method: in the figure, (a) is MF-GCI mode switching sequence, (b) is TCLC fundamental frequency equivalent reactance waveform, and (c) is converter output voltage waveform;
FIG. 3 is an MF-GCI operating waveform using an inter-mode flexible switching method: in the figure, (a) is MF-GCI mode switching sequence, (b) is TCLC fundamental frequency equivalent reactance waveform, and (c) is converter output voltage waveform.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
FIG. 1 shows a circuit topology diagram of a fault flexible arc extinction and power quality control composite system in an embodiment of the invention, which adopts a three-phase structure and three-phase symmetrical divisionEach phase of the cloth can independently run. The circuit topology comprises a Multi-function grid connected inverter (MF-GCI) and a transformer T, wherein the current injected into a power grid from the MF-GCI is
Figure BDA0003187804570000051
The grid side voltage is
Figure BDA0003187804570000052
The voltage of the power grid is
Figure BDA0003187804570000053
Current of the power grid is
Figure BDA0003187804570000054
Line to ground resistance of ra、rb、rcLine-to-ground capacitance of Coa、Cob、CocGround fault transition resistance of Rf，
Figure BDA00031878045700000512
In order to be the neutral point voltage, the voltage of the neutral point,
Figure BDA0003187804570000055
in order to be the faulty phase voltage,
Figure BDA0003187804570000056
one end of the MF-GCI is connected to a power grid through a transformer T, and the other end of the MF-GCI is grounded; the line-to-ground resistor and the line-to-ground capacitor are connected in parallel on a power grid, and the fault phase is connected to the ground through the ground fault resistor.
The MF-GCI comprises an active current converting part, an active current converting part and a passive part, wherein the active current converting part and the passive part of the active current converting part are connected in series; wherein, the output voltage of the active current converting part is
Figure BDA0003187804570000057
Comprises a Pulse Width Modulation (PWM) converter and a DC side energy storage capacitor CdcComprising a DC side energy storage capacitor CdcIs connected to the DC side of the PWM converter. The PWM converter is composed of 4 full-control device insulated gate bipolar transistors IGBT1, IGBT2, IGBT3, IGBT4 and 4 fly-wheel diodes, the IGBT and the fly-wheel diodes are connected in an anti-parallel connection mode, and a direct-current side energy storage capacitor CdcThe anode is connected with the collector of the IGBT1, and the direct current side energy storage capacitor CdcAnd the node emitter of the negative IGBT3 is connected. Active current converting part one end of the active current converting part is connected in series to the passive part through the node of the emitter of the IGBT2 and the collector of the IGBT4, and the other end is grounded through the node of the emitter of the IGBT1 and the collector of the IGBT 3.
The passive part is TCLC structure, and is composed of thyristor-controlled reactor (TCR) and capacitor C1And a filter inductance L2Comprising a TCR formed by a thyristor VT1、VT2And an inductance L1Composition, thyristor VT1And VT2Inverse parallel connection, inductance L1And thyristor VT1And VT2Formed as a whole in series, a capacitor C1Parallel connected to TCR, filter inductance L2One end of the capacitor is connected in series with the TCR and the capacitor C1The other end of the node is connected in series with an active current transformation part of the active current transformation part; the other end of the passive part TCR and the capacitor C1The node is connected to the power grid through a transformer T.
The fundamental reactance of the TCLC structure is:
Figure BDA0003187804570000058
wherein, alpha is thyristor VT1And VT2The firing angle therebetween;
Figure BDA0003187804570000059
is an inductance L1A reactance of (d);
Figure BDA00031878045700000510
is a capacitor C1A reactance of (d);
Figure BDA00031878045700000511
is an inductance L2The reactance of (c).
The control method mainly comprises the following steps:
step S1: collecting voltages of each phase and neutral point of a power grid line in real time; judging whether the power grid has single-phase earth fault
The method specifically comprises the following steps: if the phase voltages do not exceed the normal operating voltage
Figure BDA0003187804570000061
Multiplying and judging that the neutral point voltage is zero, and judging that the power grid normally operates; if the phase voltage exceeds the normal operating voltage
Figure BDA0003187804570000062
If the voltage of the neutral point is equal to the voltage of the power supply phase, the power grid is judged to have single-phase earth fault;
step S2: if the power grid is judged to be normally operated, the MF-GCI works in a reactive compensation mode, the zero-sequence voltage of the power grid is zero at the moment, and the voltage at the output end of the MF-GCI is phase voltage, namely Vsx＝ExChanging the thyristor VT1、VT2The trigger pulse makes the trigger angle alpha be 180 deg., at the time the TCLC structure presents reactance in capacitive area and flows through capacitor C1Is greater than the current through the TCR, rendering the TCLC structure capacitive; therefore, the capacitance-type reactive power compensator can be equivalent to a large capacitor, and the TCLC structure outputs a large part of capacitive reactive power to realize a reactive compensation function; in order to reduce the burden of reactive compensation of the active converter, most of the active power is directly supplied to the load by the power grid. The TCLC structure bears a larger capacitive voltage, so that the output voltage of the converter is reduced, and the effect of reducing the capacity of an active part is achieved.
Compensating current phasor injected into the grid from MF-GCI according to circuit kirchhoff's law
Figure BDA0003187804570000063
Comprises the following steps:
Figure BDA0003187804570000064
wherein x is a, b, c;
Figure BDA0003187804570000065
is the grid side voltage phasor; j is an imaginary unit; xTCLCIs the fundamental frequency reactance of the TCLC structure;
Figure BDA0003187804570000066
the output voltage phasor of the active current transforming part is
Figure BDA0003187804570000067
Wherein, delta is the voltage phasor of the power grid side
Figure BDA0003187804570000068
Phasor with output voltage of active current converting part
Figure BDA0003187804570000069
The included angle between them;
the following formulas (2) and (3) can be obtained:
Figure BDA00031878045700000610
wherein, VsxIs the grid side voltage; i isRActive current injected into the grid for MF-GCI; i ismReactive current injected into the grid for the MF-GCI.
Active current converting part the output voltage V of the active current converting partinvxComprises the following steps:
Figure BDA0003187804570000071
when the power grid normally operates, in order to reduce the capacity of the active current converting part to the minimum, the voltage V output by the active current converting part of the active current converting part needs to be controlledinvxTo the minimum, pairCurrent phasor injected into power grid by MF-GCI
Figure BDA0003187804570000072
Fundamental reactance X for TCLC structureTCLCThe derivation is carried out and is made to be zero, so that the output voltage V of the active current converting part can be obtainedinvxMinimizing the fundamental reactance X of the TCLC structureTCLCIs composed of
Figure BDA0003187804570000073
From active power injected into the grid from the MF-GCI is
P＝VsxIR (7)
The reactive power injected into the grid from the MF-GCI is:
Q＝VsxIm (8)
substituting equations (7) and (8) into equation (6) can yield:
Figure BDA0003187804570000074
in the reactive compensation mode, the MF-GCI only provides reactive power and active power is provided by the power supply, and the MF-GCI does not inject active power, that is: p is 0, does not flow through the electric current on the TCR this moment, and the capacitive reactance of TCLC structure is minimum, and the capacitive reactive power of the maximum compensation is corresponded to TCLC structure this moment, and then the minimum reactance of TCLC structure is:
Figure BDA0003187804570000075
wherein Q isTCLC(max)Is the maximum reactive power injected into the grid from the MF-GCI;
Figure BDA0003187804570000076
is an inductance L2A reactance of, and XL2＝jωL2，L2Is an inductance L2The inductance of (2);
Figure BDA0003187804570000077
is a capacitor C1The reactance of (a), namely:
Figure BDA0003187804570000078
omega is angular frequency, C1Is a capacitor C1The capacitance of (c).
To meet the reactive compensation requirement, the reactive power injected into the power grid by the MF-GCI needs to be greater than or equal to the reactive power required by the load for compensation, that is:
QTCLC(max)≥QL (11)
wherein Q isLReactive power that needs to be compensated for the load.
The capacitance-reactance minimum capacitance C of the TCLC structure under the reactive compensation mode can be obtained by the formulas (9) to (11)1Comprises the following steps:
Figure BDA0003187804570000081
wherein L is2Is a filter inductor L2The inductance and omega are fundamental angular frequency;
in a reactive compensation mode, the active part controls the output voltage of the converter to be zero, and at the moment, the trigger pulse of the thyristor is changed to further change the trigger angle alpha of the TCLC to be 180 degrees, so that the current completely flows through the TCLC capacitor C1The TCLC structure now compensates for the full reactive power.
And step S3, if the power grid judges that the single-phase earth fault occurs, locking the MF-GCI for one period, and then realizing the MF-GCI flexible switching. After being locked for a period of time, the MF-GCI is controlled to inject arc suppression current, and the thyristor VT is controlled1And VT2The trigger angle between the two is alpha-90 degrees, the thyristor is fully conducted and is equivalently inductance L1Capacitor C1Parallel connection to make the current flowing through TCR larger than the capacitance C1The current flowing upwards makes the TCLC structure reactance be located in the inductive area, and the TCLC structure presents the inductive property at the moment, so the TCLC structure can be equivalent to a large inductor to bear inductive reactive power, thereby reducing the capacity of the active part. At the same time, MF-GCI passes through the active partAnd arc extinction current is injected in a sub-control mode to suppress the fault phase voltage to be zero, so that arc extinction is realized.
By two locking modes, namely: the upper bridge arm IGBT1 and the IGBT2 are switched on, and the lower bridge arm IGBT3 and the IGBT4 are switched off; the upper leg IGBT1 and IGBT2 turn off, and the lower leg IGBT3 and IGBT4 turn on. And locking the IGBT of the active part, and controlling the MF-GCI to inject arc suppression current after locking for a period of time, thereby realizing the flexible switching of the MF-GCI.
The method specifically comprises the following steps: when single-phase earth fault occurs, the fault phase MF-GCI quits operation, the rest non-fault phase is injected with compensating current, and the non-fault phase MF-GCI bears line voltage, namely
Figure BDA0003187804570000082
The maximum injected inductive arc suppression current is maximum when the TCLC reactance is minimum, and the minimum reactance of the TCLC structure is as follows:
Figure BDA0003187804570000083
wherein, Im(max)The maximum arc extinction active current is injected for the non-fault phase MF-GCI; i isR(max)The maximum arc-extinguishing reactive current is injected for the non-fault phase MF-GCI; in order to suppress the earth fault current to be zero and realize a good arc extinction effect, the following requirements are met:
Figure BDA0003187804570000091
wherein: r isxIs a non-fault phase line resistance to ground, C0xThe non-fault phase line is a ground capacitor; exIs the supply voltage;
inductance L of TCLC structure1Comprises the following steps:
Figure BDA0003187804570000092
wherein, C1A capacitance that is a TCLC structure;
wherein L is2Is an inductance L2For reducing current ripple of the MF-GCI output, and
Figure BDA0003187804570000093
wherein, VdcxIs the DC side capacitor voltage, fsFor switching frequency, Δ icxmaxThe current is injected for the maximum ripple allowed by the MF-GCI.
And reducing the injected compensation current after a period of time, if the neutral point voltage is reduced, indicating that the fault is eliminated, otherwise indicating that the fault still exists, and isolating the fault feeder line.
And step S4, returning to step S1 and continuing to execute.
The MF-GCI operating waveform without the inter-mode flexible switching method is shown in FIG. 2, at t0～t1Meanwhile, the MF-GCI works in a reactive compensation mode, and the TCLC is capacitive; at t1When a single-phase earth fault happens at any moment, the active part and the passive part of the MF-GCI act simultaneously; at t1～t2During the period, MF-GCI is switched to an arc extinction mode, after arc extinction current is injected, the grounding fault current is well inhibited, and at the moment, TCLC is inductive; at t2At the moment, the fault is eliminated, the active part and the passive part of the MF-GCI act simultaneously, the MF-GCI is switched to a reactive compensation mode, and the TCLC is capacitive.
According to the TCLC fundamental frequency equivalent reactance waveform, when different modes are switched, the reactance cannot be instantly adjusted to a stable value. When switching from the reactive compensation mode to the arc extinction mode, the reactance of the TCLC gradually increases. When switching from arc extinction mode to reactive compensation, the reactance of the TCLC increases and then decreases. Finally, the output voltage of the converter is stabilized through the reactance adjustment process. If the output voltage of the converter is instantly increased in the process of switching the MF-GCI from the reactive compensation mode to the arc extinction mode according to the ideal action logic, the safe operation of the MF-GCI is seriously influenced.
To solve the above problem, the MF-GCI is locked for one cycle (Δ t ═ 0.02s) when a single-phase ground fault occurs.Fig. 3 shows the active and passive parts of the MF-GCI operating in coordination when latch-up is added. At t1At the moment, locking the MF-GCI; t is t1～t2For the duration of the latch-up, the IGBTs 1 and 2 are turned on and the IGBTs 3 and 4 are turned off. TCLC carries out reactance adjustment, and MF-GCI does not inject current at the moment, and the output voltage of the converter is reduced to zero. After the locking time of delta t, TCLC reactance adjustment is basically finished, at the moment, MF-GCI injects arc extinction current, and the output voltage of the converter is recovered to a steady-state value. Therefore, the instantaneous rise of the output voltage of the converter when the MF-GCI is switched from the reactive compensation mode to the arc extinction mode is effectively avoided.
All the embodiments in the present specification are described in a related manner, and the same and similar parts among the embodiments may be referred to each other, and each embodiment focuses on the differences from the other embodiments. In particular, for the system embodiment, since it is substantially similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.

Claims (8)

1. The optimized operation and control method of the fault flexible arc extinction and power quality regulation and control composite system is characterized in that the fault flexible arc extinction and power quality regulation and control composite system comprises a grid-connected converter, and the grid-connected converter is formed by connecting an active current conversion part and a passive part in series;
the passive part is a TCLC structure, and the reactor and the capacitor C are controlled by a thyristor1And a filter inductance L2The thyristor-controlled reactor is formed by a thyristor VT1、VT2And an inductance L1Composition, thyristor VT1And VT2Inverse parallel connection, inductance L1And thyristor VT1And VT2Formed as a whole in series, a capacitor C1Reactor controlled by thyristorParallel filter inductor L2One end of the reactor is connected in series with a thyristor controlled reactor and a capacitor C1On the node of (2); filter inductance L2The other end is connected in series with an active current transformation part of the active current transformation part;
the method comprises controlling thyristor VT when the power grid is in normal operation1And VT2The trigger angle of (a) is 180 DEG, so that the TCLC structure presents the capacitance, and the capacitance reactance and the capacitance C of the TCLC structure are set1The TCLC structure compensates all reactive power;
when the single-phase earth fault occurs in the power grid, the thyristor VT is controlled1And VT2The trigger angle of (a) is 90 DEG, the TCLC structure is inductive, and the reactance and inductance L of the TCLC structure are set1And an inductance L2The TCLC structure injects a maximum inductive crowbar current.
2. The optimal operation and control method of the fault flexible arc extinction and power quality regulation combined system according to claim 1, wherein the reactance of the TCLC structure is as follows when a power grid normally operates:
Figure FDA0003187804560000011
wherein, VsxThe grid side voltage, x ═ a, b, c; qTCLC(max)The maximum reactive power injected into the power grid from the grid-connected converter;
Figure FDA0003187804560000013
is an inductance L2A reactance of (d);
Figure FDA0003187804560000014
is a capacitor C1The reactance of (c).
3. The method for optimizing operation and control of a fault-tolerant arc extinction and power quality control combined system according to claim 1, wherein the capacitor C is used for controlling the fault-tolerant arc extinction and power quality control system1During normal operation of the gridComprises the following steps:
Figure FDA0003187804560000012
wherein E isxIs the grid voltage; l is2Is a filter inductor L2The inductance and omega are fundamental angular frequency; qTCLC(max)Is the maximum reactive power injected into the grid from the grid-connected converter.
4. The optimal operation and control method of the fault flexible arc extinction and power quality control combined system according to the claim 2 or 3, wherein the maximum reactive power injected into the power grid from the grid-connected converter is greater than or equal to the reactive power required by the load to compensate.
5. The method for optimizing operation and control of a fault-tolerant arc extinction and power quality control combined system according to claim 1, wherein the grid-connected converter controls a thyristor VT after being locked for one period when a single-phase earth fault occurs in a power grid1And VT2The trigger angle between the two is alpha-90 degrees, the thyristor is fully conducted and is equivalently inductance L1Capacitor C1In parallel connection, the current flowing through the thyristor controlled reactor is larger than the capacitor C1The current flowing therethrough.
6. The optimal operation and control method of the fault flexible arc extinction and power quality regulation combined system according to claim 1, wherein when a single-phase earth fault occurs in a power grid, the reactance of the TCLC structure is as follows:
Figure FDA0003187804560000021
wherein, Im(max)The maximum arc extinction active current is injected for the non-fault phase MF-GCI; i isR(max)The maximum arc-extinguishing reactive current is injected for the non-fault phase MF-GCI;
Figure FDA0003187804560000022
is an inductance L1A reactance of (d);
Figure FDA0003187804560000023
is a capacitor C1A reactance of (d);
Figure FDA0003187804560000024
is an inductance L2A reactance of (d); and is
Figure FDA0003187804560000025
Wherein: r isxIs a non-fault phase line resistance to ground, C0xThe non-fault phase line is a ground capacitor; exIs the supply voltage.
7. The method for optimizing operation and control of a fault-tolerant arc extinction and power quality regulation combined system according to claim 1, wherein an inductance L of the TCLC structure is set1The inductance of (a) is:
Figure FDA0003187804560000026
wherein, C1A capacitance that is a TCLC structure;
L2is an inductance L2For reducing current ripple of the MF-GCI output, and
Figure FDA0003187804560000027
wherein, VdcxIs the DC side capacitor voltage, fsFor switching frequency, Δ icxmaxThe current is injected for the maximum ripple allowed by the MF-GCI.
8. The optimal operation and control method of the fault flexible arc extinction and power quality regulation combined system according to claim 5, wherein the grid-connected converter is locked when a single-phase earth fault occurs in a power grid as follows: switching on an upper bridge arm of an active current converting part of the active current converting part and switching off a lower bridge arm of the active current converting part; or closing the upper bridge arm of the active current converting part and simultaneously conducting the lower bridge arm of the active current converting part;
the active current converting part consists of a pulse width modulation converter and a direct current side energy storage capacitor, and the direct current side energy storage capacitor is connected to the direct current side of the pulse width modulation converter; the pulse width modulation converter is composed of 4 full-control device insulated gate bipolar transistors IGBT1, IGBT2, IGBT3, IGBT4 and 4 freewheeling diodes, the IGBT and the freewheeling diodes adopt an anti-parallel connection mode, the anode of a direct-current side energy storage capacitor is connected with the collector of the IGBT1, and the node emitter of the cathode of the direct-current side energy storage capacitor IGBT3 is connected; active current converting part one end of the active current converting part is connected in series to the passive part through the node of the emitter of the IGBT2 and the collector of the IGBT4, and the other end is grounded through the node of the emitter of the IGBT1 and the collector of the IGBT 3.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023066470A1 (en) * 2021-10-19 2023-04-27 Abb Schweiz Ag Stabilizing electrical power in an electrical grid

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070014132A1 (en) * 2005-07-18 2007-01-18 Zhaoan Wang Comprehensive power quality controller for substation in power system
CN101202447A (en) * 2007-12-19 2008-06-18 湖南大学 Method for eliminating and controlling SVC specific times harmonic advanced research and apparatus realizing the same
CA2768101A1 (en) * 2009-09-15 2011-03-24 The University Of Western Ontario Utilization of distributed generator inverters as statcom
CN102611117A (en) * 2012-02-29 2012-07-25 澳门大学 LC-VSI device reactive compensation control method based on self-adaptive control DC side voltage
CN202495771U (en) * 2012-03-29 2012-10-17 徐州润泽电气有限公司 Active full-compensation arc-suppression coil device
CN102832630A (en) * 2012-09-07 2012-12-19 南车株洲电力机车研究所有限公司 Integrated governance device for electric energy quality
CN104319769A (en) * 2014-10-28 2015-01-28 国网辽宁省电力有限公司朝阳供电公司 SVG active filtering control method
CN107749639A (en) * 2017-09-30 2018-03-02 澳门大学 Mixed type network-connecting generation inverter system equipped with power quality compensation

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070014132A1 (en) * 2005-07-18 2007-01-18 Zhaoan Wang Comprehensive power quality controller for substation in power system
CN101202447A (en) * 2007-12-19 2008-06-18 湖南大学 Method for eliminating and controlling SVC specific times harmonic advanced research and apparatus realizing the same
CA2768101A1 (en) * 2009-09-15 2011-03-24 The University Of Western Ontario Utilization of distributed generator inverters as statcom
CN102611117A (en) * 2012-02-29 2012-07-25 澳门大学 LC-VSI device reactive compensation control method based on self-adaptive control DC side voltage
CN202495771U (en) * 2012-03-29 2012-10-17 徐州润泽电气有限公司 Active full-compensation arc-suppression coil device
CN102832630A (en) * 2012-09-07 2012-12-19 南车株洲电力机车研究所有限公司 Integrated governance device for electric energy quality
CN104319769A (en) * 2014-10-28 2015-01-28 国网辽宁省电力有限公司朝阳供电公司 SVG active filtering control method
CN107749639A (en) * 2017-09-30 2018-03-02 澳门大学 Mixed type network-connecting generation inverter system equipped with power quality compensation

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
CHI-SENG LAM: "Adaptive Thyristor-Controlled LC-Hybrid Active Power Filter for Reactive Power and Current Harmonics Compensation With Switching Loss Reduction", 《IEEE TRANSACTIONS ON POWER ELECTRONICS》 *
LEI WANG ETC: "Modeling and Parameter Design of Thyristor-Controlled LC-Coupled Hybrid Active Power Filter (TCLC-HAPF) for Unbalanced Compensation", 《IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS》 *
LEI WANG: "Design of A Thyristor Controlled LC Compensator for Dynamic Reactive Power Compensation in Smart Grid", 《IEEE TRANSACTIONS ON SMART GRID》 *
谭真: "耦合可控电抗器的统一电能质量控制器", 《电力自动化设备》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023066470A1 (en) * 2021-10-19 2023-04-27 Abb Schweiz Ag Stabilizing electrical power in an electrical grid

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