CN101924370A

CN101924370A - A kind of mixed type power quality controlling device

Info

Publication number: CN101924370A
Application number: CN2010102756513A
Authority: CN
Inventors: 王卫安; 黄燕艳; 张定华; 谭胜武; 周方圆; 胡晓东; 周靖; 刘华东; 易海泉; 杨磊; 王才孝; 段世彦; 邓建华; 吕顺凯; 龙礼兰
Original assignee: Zhuzhou National Engineering Research Center of Converters Co Ltd
Current assignee: Zhuzhou National Engineering Research Center of Converters Co Ltd
Priority date: 2010-09-08
Filing date: 2010-09-08
Publication date: 2010-12-22
Anticipated expiration: 2030-09-08
Also published as: CN101924370B

Abstract

The invention discloses a kind of mixed type power quality controlling device, comprise active and passive part, active part comprises Active Power Filter-APF APF, and static reacance generator SVG, SVG are used to provide the transient state reactive power, and APF is used for the filtering harmonic wave; APF and SVG have and are no less than two groups, and are connected with three phase network by the transformer isolation mode with parallel form; Passive part comprises Static Var Compensator SVC, and SVC is used to provide the stable state reactive power; SVC comprises thyristor switchable capacitor TSC, thyristor-controlled reactor TCR, and fixed capacity compensation FC, TSC, TCR, FC all directly link to each other with three phase network; TSC is used to provide big capacity capacitive reactive power, and FC is used to provide the low capacity reactive power, and the double main subharmonic filter branch of being TCR, is used for comprehensive compensation and harmonic wave control are coordinated by the electric energy system.

Description

Mixed type electric energy quality treatment device

Technical Field

The invention relates to a power quality control device, in particular to a novel parallel hybrid active and passive power quality control device applied to a power supply and distribution system.

Background

The quality of the electric energy of the power supply and distribution system is directly related to the stability of the electric power system, the safety of electric equipment and whether the electric equipment is economical or not. With the increasing use of power electronic devices and sensitive loads, the problem of power quality has become the first technical problem concerned by the international power supply world, which is mainly reflected in the fluctuation, harmonic waves, flicker and the like of voltage, and the influence of reactive power, negative sequence, harmonic components and the like in current. The control on the quality of the electric energy can inhibit the voltage fluctuation, flicker and the like of a power distribution system, improve the equipment productivity, reduce the line loss and improve the equipment utilization rate, thereby realizing the purposes of energy conservation and consumption reduction. In order to solve the problem, a series of treatment devices appear in succession, and are mainly classified into series connection, parallel connection or a mixed type thereof, wherein the parallel connection type has the advantages of convenient switching and simple protection, and becomes the key point of research of numerous companies, including TSC (Thyristor Switched capacitor), TCR (Thyristor Controlled Reactor), APF (Active Power Filter), SVG (Static Var Generator), and HAPF (Hybrid Active Power Filter). The TSC and the TCR use a thyristor of a half-control device as a switching device, the response time is generally 1-2 power frequency periods, the TSC is graded compensation, and partial compensation of certain harmonic is taken into consideration sometimes, so that the TSC and the TCR are suitable for occasions with small load fluctuation; the TCR must be matched with TSC or FC (Fixed capacitor compensation), and has the advantages of continuous and adjustable reactive power, but the TCR is also a harmonic source and poor filtering effect; the APF and SVG use an Insulated Gate Bipolar Transistor (IGBT) or an Integrated Gate-Commutated Thyristor (IGCT) as a switching device, and the response time is much faster than that of the TSC and the TCR, but because of the limitation of the voltage and current levels of the fully controlled device, the high voltage and the high capacity require the parallel connection and the series connection of tens of devices, the cost and the control complexity are high, and the reliability is poor, so the APF and the SVG are generally used in low voltage and small capacity occasions at present; while HAPF does not dynamically adjust the reactive power output in practice, because it improves part of the equivalent capacity with the FC variable.

The following documents are mainly relevant to the present patent application in the prior art:

the first document is a chinese patent application publication document published by the limited liability company of sienna saibo electrical on the 26 th 6 th 2009, the 25 th 11 th 2009, and the publication number CN101588069, based on bidirectional dynamic nothingThe harmonic and reactive comprehensive compensation system of the power compensation device specifically introduces a parallel system formed by a Mechanically Switched Capacitor MSC (Mechanically Switched Capacitor), a static var generator SVG and an active power filter APF, as shown in fig. 1. The method utilizes APF to control harmonic waves, utilizes MSC to reduce the capacity of the SVG, and compared with the single practical SVG, the capacity of the SVG can be reduced by half. And compared with the mode shown in fig. 2, SVG is adopted to replace TCR, thus the burden of APF is reduced, because TCR brings harmonic waves, and SVG does not. The system mainly utilizes SVG to operate in inductive and capacitive modes, and utilizes MSC to provide capacitive mode, so that a wider capacitive operation space can be provided. This way, the compensation capacity of the SVG can be reduced by half, but for the large capacity actually required, the SVG capacity is still large and the cost is high. Moreover, the single unit in the figure is difficult to realize high pressure and large capacity and is only suitable for a low-pressure small-capacity system. The voltage level limitation of the active receiver device of the whole system is only suitable for low-voltage systems. And because MSC can not be switched frequently, under the no-load condition, SVG needs rated operation, and no-load loss is big.

Document two is a chinese patent application publication document of chinese invention CN101183791, published by the university of Hunan on 2007 on 19.12.21.2008, a combined operation system of a static var compensator and an active power filter and a control method thereof, and specifically introduces a compensation system and a control method thereof, which combines a TCR and a HAPF, wherein the TCR and the FC part in the HAPF form an SVC (static var compensator) for harmonic compensation, and the APF is matched with the FC for filtering harmonic, as shown in fig. 3. The system and the control method utilize TCR to cooperate with FC in HAPF for reactive power management, and APF cooperates with FC for reactive power compensation. The HAPF cannot dynamically compensate reactive power, so that dynamic reactive power adjustment depends on TCR control, the response time of the TCR ranges from 60 ms to 100ms, and the suppression effect of the speed on voltage flicker is poor. And this HAPF approach is complex in construction and is not suitable for high pressure systems. And when the device is in idle running, the TCR is carried at rated current, and the idle loss is high.

The third document is applied by the university of Hunan on the 19 th 12 th 2007, the 10 th 2008, the publication is granted on the 10 th 12 th, and the Chinese utility model with the publication number of CN201163721Y, based on the combined operation device of the static var compensator and the hybrid injection active filter, specifically discloses a reactive power compensation device which combines the TCR + TSC type SVC and the HAPF, and the FC part in the SVC and the HAPF constitutes the SVC with large capacity to perform reactive power compensation, and the APF is matched with the FC to filter harmonic waves, as shown in FIG. 4. The device adds a set of TSCs on the basis of the patent CN101183791, so that the reactive compensation range is enlarged, the capacity of the TCR is reduced, and partial no-load loss is reduced. However, since the TCR is used to control the idle operation, the effect of suppressing flicker is poor. Also, there is a large idle loss since the TCR must be matched to the FC in the HAPF.

In the fourth document, a new STATCOM voltage control method applied to an unbalanced system is mainly disclosed in a new STATCOM voltage control method applied to the unbalanced system, which is published by a paper "new electrotechnical science report" in the third phase 2010 of luo an, n paniculate swallow, a double loop control method is often adopted when a Static Synchronous Compensator (Static Synchronous Compensator) STATCOM (Static Synchronous Compensator) stabilizes the access point voltage, but the method has a plurality of PI regulators, is difficult to implement, and does not consider the problem of three-phase imbalance of the grid voltage. The instantaneous power balance principle is adopted, a reference current signal is directly converted into a reference voltage signal, a current inner loop PI regulator in the traditional double-loop control is omitted, a negative sequence voltage feedforward link is introduced to maintain the access point voltage to keep three-phase balance, and an algebraic relation between the inverter output voltage and the output current under the condition of negative sequence voltage is deduced. Considering that the instantaneous power balance principle requires the equivalent resistance and the equivalent inductance of the STATCOM, and the two parameter values are generally difficult to measure accurately, the measured values of the two parameters are continuously corrected according to the feedback information. The method utilizes instantaneous power balance to directly replace the traditional double closed loop control, and then continuously corrects the measured values of the equivalent resistance and the equivalent inductance according to feedback information. Thus, correction has a delay, which affects the accuracy of control and is not robust.

The fifth document is a study on the device modeling, control and simulation of the static synchronous compensator (STATCOM) published by the article "static synchronous compensator device modeling, control and simulation research" in the journal of system simulation, journal of 10 of 2007 by the name of tomahagnet, grandyukun, wu aihua, grandyun. And establishing a time domain mathematical model and a steady state mathematical model of the STATCOM device by using an input and output modeling method and an energy equation. According to a mathematical model, two STATCOM reactive current control strategies are provided. The modeling of the STATCOM control system is realized by using a Matlab/Simulink platform. The simulation result verifies the correctness of the mathematical model and the effectiveness of the control strategy. The method utilizes the traditional double closed-loop control, and the control mode has high complexity in adjusting a plurality of PIs.

Therefore, in order to meet the urgent requirements of improving the quality of electric energy and saving the energy of the electric energy, a low-cost comprehensive compensation device which has high capacity, can compensate voltage flicker, power factors, three-phase imbalance and the like and can effectively inhibit harmonic waves is researched, and the low-cost comprehensive compensation device has great practical significance and market popularization value.

Disclosure of Invention

The embodiment of the invention provides a hybrid electric energy quality control device, which has larger compensation capacity, can compensate voltage flicker, power factors, three-phase imbalance and the like, and can perform low-cost comprehensive compensation for effectively inhibiting harmonic waves.

The invention provides a concrete implementation mode of a mixed type power quality control device, which comprises the following components: the active part comprises an active power filter APF and a static var generator SVG, wherein the static var generator SVG is used for providing transient reactive power, and the active power filter APF is used for filtering harmonic waves; the active power filter APF and the static var generator SVG are not less than two groups and are connected with a three-phase power grid in a parallel connection mode in a transformer isolation mode; the passive part comprises a Static Var Compensator (SVC) which is used for providing steady-state reactive power; the static var compensator SVC comprises a thyristor switched capacitor TSC, a thyristor controlled reactor TCR, a fixed capacitance compensation FC, a thyristor switched capacitor TSC, a thyristor controlled reactor TCR and a fixed capacitance compensation FC which are all directly connected with a three-phase power grid; the thyristor switched capacitor TSC is used for providing high-capacity capacitive reactive power, the fixed capacitor compensation FC is used for providing low-capacity reactive power, and the fixed capacitor compensation FC is also used as a main subharmonic filtering branch of the thyristor controlled reactor TCR.

As a further embodiment of the present invention, a hybrid power quality management apparatus includes: the SVC control module comprises a B point split-phase reactive power calculation module, a first proportional integral module, a TSC switching control module, a calculation module of each phase control angle, and a voltage

And current i_BAnd the phase-splitting reactive power calculation module of the point B is input, TSC switching control signals are obtained through the first proportional-integral module and the TSC switching control module, and the phase-splitting control signals of the TCR are obtained by entering each phase control angle calculation module according to the reactive power required to be generated by the TCR.

As a further embodiment of the present invention, a hybrid power quality management apparatus includes: the active power filter APF control module comprises a reactive harmonic compensation judgment module, a target harmonic detection module, a harmonic and direct current voltage PI regulation module and a voltage

And current i_BThe input reactive harmonic compensation judgment module calculates a target harmonic to be compensated, outputs the target harmonic obtained through calculation, performs proportional integral control with the transmitted harmonic input harmonic and the direct current voltage PI regulation module, determines a reference voltage, and generates a pulse to trigger an active source by comparing the reference voltage with a fixed triangular waveThe individual modules in the power filter APF.

As a further embodiment of the present invention, a hybrid power quality management apparatus includes: the static var generator SVG control module comprises a self-adaptive fuzzy controller, a reactive current direct calculation module and an instantaneous power balance-based double-closed-loop PI control module, and the instantaneous power balance-based double-closed-loop PI control module obtains a control signal of the static var generator SVG according to output signals of the self-adaptive fuzzy controller and the reactive current direct calculation module.

As a further embodiment of the present invention, a hybrid power quality management apparatus includes: the SVG double closed-loop voltage control module based on the self-adaptive fuzzy control and the instantaneous power balance comprises a current inner loop, a voltage outer loop and a current-voltage conversion module based on the instantaneous power balance, and outputs current i_cFed back to the current inner loop, phase e of a_aThe current input circuit enters a current inner ring through a phase locking module and a sine and cosine conversion module, two paths of output signals from a voltage outer ring including one path of output signals from an adaptive fuzzy controller pass through a first amplitude limiting module group and are respectively subjected to difference value operation with two paths of output signals from the current inner ring, the output difference values enter a current pressure conversion module based on instantaneous power balance after passing through a first PI adjusting module group and a second amplitude limiting module group, and the current pressure conversion module based on instantaneous power balance outputs signals to a second coordinate conversion module through calculation.

As a further embodiment of the invention, the adaptive fuzzy controller comprises a fuzzy controller and a neural network predictor, and the input of the fuzzy controller is bus voltageDifference from target voltageAnd

output as the change amount of the target reactive current

The neural network predictor is used for predicting the voltage difference according to K, K-1 and K-2 moments

And the actual amount of output reactive current

Predicting the bus voltage difference at the moment K +1

Thereby adjusting the regularity factor of the fuzzy controller.

As a further embodiment of the present invention, a hybrid power quality management apparatus includes: the double closed-loop control module for instantaneous power balance based on instantaneous reactive current PI control comprises a current inner loop, a voltage outer loop and a current-voltage conversion module based on instantaneous power balance, and outputs current i_cFed back to the current inner loop, phase e of a_aOne path enters a current inner ring after passing through a phase locking module and a sine and cosine conversion module, and the other path is connected with a current i_a，i_b，i_cThe output difference value is subjected to difference value operation with two paths of output signals from a current inner ring after passing through a PI adjusting module group I and a limiting module group II, and then enters a current balance based current pressure conversion module, and is output to a coordinate conversion module II through calculation based on the current balance current pressure conversion module.

As an originalIn a further embodiment of the present invention, a hybrid power quality management apparatus includes: a PWM module which is a sine pulse width modulation module and outputs signals of a coordinate conversion module

And after the triangular wave is compared with the triangular wave through a PWM module, a trigger signal of each phase module of the SVG is obtained and is output to a voltage source inverter to form a compensation current so as to compensate the electric energy quality of the load.

As a further embodiment of the present invention, the sinusoidal pulse width modulation module comprises: and when the modulation wave and the carrier are compared at an intersection point and turned over, the narrow pulse eliminating module immediately locks and prohibits the PWM signal from turning over before unlocking.

As a further embodiment of the present invention, a hybrid power quality management apparatus includes: switching device frequency conversion module, switching device frequency conversion module links to each other with SVG for the frequency of switching device in sending different reactive current and the conversion change SVG between harmonic current is sent to change SVG, and change and allow SVG to send the peak value of reactive current, protection device does not overflow and overvoltage.

By applying the hybrid power quality management device described by the embodiment of the invention, the reactive power required by the load in a steady state is mainly compensated by using the large capacity of the SVC, three-phase unbalance compensation is carried out, the dynamic reactive power or voltage in compensation is quickly reacted by using the rapidity of the small capacity of the SVG/APF so as to inhibit voltage fluctuation and flicker, meanwhile, the APF part of the SVC is matched with the FC in the SVC to carry out harmonic management, and the effect of coordinating and using the small-capacity active power and the large-capacity passive power to realize low-cost large-capacity power quality compensation can be achieved.

Drawings

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 an electrical schematic diagram of a prior art harmonic and reactive integrated compensation system based on a bi-directional dynamic reactive compensation device;

FIG. 2 is an electrical schematic diagram of a hybrid system based on APF and TCR and MSC of the prior art;

FIG. 3 is an electrical schematic diagram of a prior art static var compensator and active power filter combined operation system;

FIG. 4 is an electrical schematic diagram of a prior art co-operating device based on a static var compensator and a hybrid injection active filter;

FIG. 5 is an electrical schematic diagram of a topological structure of a hybrid power quality management device of the present invention;

FIG. 6 is a schematic diagram of a single-phase equivalent model circuit of a hybrid power quality management device of the present invention;

FIG. 7 is a block diagram of the control principle of a hybrid power quality management device of the present invention;

FIG. 8 is a schematic block diagram of SVG double closed-loop voltage control based on adaptive fuzzy control and instantaneous power balance for a hybrid power quality management device of the present invention;

FIG. 9 is a schematic block diagram of a voltage adaptive fuzzy controller of a hybrid power quality management device according to the present invention;

FIG. 10 is a schematic diagram of the dual closed-loop control based on instantaneous reactive current PI control and instantaneous power balance of a hybrid power quality management device of the present invention;

FIG. 11 is a schematic diagram of a narrow pulse waveform at the rising edge of a carrier of a hybrid power quality management device according to the present invention;

FIG. 12 is a schematic diagram of a narrow pulse waveform at the carrier falling edge of a hybrid power quality management device according to the present invention;

FIG. 13 is a schematic waveform diagram of an unlocking mechanism of a hybrid power quality management device according to the present invention;

FIG. 14 is a schematic diagram of a hybrid power quality management device according to the present invention without a locking mechanism;

FIG. 15 is a schematic diagram of a hybrid power quality management device according to the present invention, showing a waveform of a locking mechanism;

wherein, the 1-B point split-phase reactive power calculation module, the 2-proportional integral module I, the 3-TSC switching control module, the 4-each phase control angle calculation module, the 5-reactive harmonic compensation judgment module, the 6-target harmonic detection module, the 7-harmonic and direct current PI regulation module, the 8-adaptive fuzzy controller, the 9-reactive current direct calculation module, the 10-instantaneous power balance based double closed loop PI control module, the 11-amplitude limiting module group I, the 12-PI regulation module group I, the 13-amplitude limiting module group II, the 14-PWM module, the 15-voltage source inverter, the 16-coordinate transformation module II, the 17-fuzzy controller, the 18-neural network predictor, the 19-coordinate transformation module I, the 20-low pass filter group I, the system comprises a first 21-PI controller, a 22-phase locking module and a 23-sine and cosine conversion module.

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.

As a specific implementation of the hybrid power quality management device of the present invention, the electrical schematic diagram of the topology structure shown in fig. 5 specifically discloses a circuit topology structure of the hybrid power quality management device. Considering that the system response time of a compensation device required for flicker management is within a power frequency period, and combining the maturity and cost performance of the prior art, a novel parallel hybrid active and passive power quality compensation device (PMAPPQC) which is formed by combining a transformer coupling type multiple SVG/APF and a direct hanging type SVC is adopted, the large capacity of the transformer coupling type multiple SVG/APF is utilized to mainly compensate reactive power required by a load in a steady state, three-phase imbalance compensation is carried out, the rapidity of the small capacity of the transformer coupling type multiple SVG/APF is utilized to rapidly react to dynamic reactive power or voltage in compensation so as to inhibit voltage fluctuation and flicker, meanwhile, the APF part of the transformer coupling type multiple SVC is utilized to carry out harmonic management, and the small capacity active and large capacity passive are utilized to realize low-cost large capacity power quality compensation. The following describes a practical problem handling method in control and engineering applications in combination with the described scheme.

The SVC is not limited by voltage classes, and the SVG and the APF are isolated by the transformer, so that the SVC can be applied to systems with various voltage classes. Meanwhile, the SVC comprises TCR, TSC and FC, wherein the TSC provides large-capacity capacitive reactive power, and the FC provides small-capacity reactive power and is also used as a main subharmonic filtering branch of the TCR. Therefore, when the device is in no-load, the TCR only needs to be mutually compensated with the FC with small capacity, the running loss and no-load loss are less, and the FC is used for filtering partial harmonic waves, so that the harmonic wave filtering function of the APF is reduced. The whole SVC realizes the treatment of negative sequence by controlling TCR. And SVG mainly compensates the reactive power after SVC compensation not enough, and SVC provides steady state reactive power promptly, and SVG provides transient state reactive power, and the capacity of SVG that needs like this is less. With the increase of load, the SVG adopts a multiple parallel connection mode, so that the capacity can be doubled and the equivalent switching frequency can be improved. Also, the APF can expand the compensation capacity by multiplexing. And the SVG can change the switching frequency when the reactive compensation quantity is less, and realize the function improvement harmonic wave of part APF.

As shown in fig. 5, the PMAPPQC is mainly divided into two parts, active based on fully controlled devices and passive based on semi-controlled or uncontrolled devices. The passive part is added mainly to reduce the capacity of the active part and save the cost, and the passive part and the active part achieve the same effect of independently using high-capacity active compensation through cooperative control. The active part adopts a transformer isolation multiplexing technology, and the active part is decomposed into multiple SVG and multiple APF due to different switching devices, connecting reactance and the like, wherein the SVG mainly compensates reactive current, the APF compensates harmonic current, and the APF can also be used as a reactive generator to make up for the deficiency of SVG capacity when the voltage drop is serious. Both adopt a multiplexing technology, so that the voltage and current levels of the required power devices can be reduced only by selecting proper coupling transformer transformation ratio and converter weight according to the actual compensation requirement, thereby avoiding numerous problems caused by adopting a series-parallel connection mode of the power devices for realizing large capacity; moreover, a low-power device with higher switching frequency is adopted, so that the price is low, the control precision of the device is high, the response is rapid, and the equivalent switching frequency is improved through carrier phase shift; in addition, because each inversion module does not have direct electrical connection, under the redundant condition, if some modules are cut off due to faults, other modules can rapidly and automatically make up for the difference through regulation and control, and the device can work in a derating mode. In the passive part, the TCR, the TSC and the FC are combined into a large-capacity direct hanging type SVC for reactive compensation, and three-phase asymmetry is compensated by controlling the three-phase asymmetry of the TCR. The TSC is added to reduce the capacity of the TCR, and simultaneously, the TSC and the FC are used as filtering branches of certain subharmonics, and the TSC can be divided into a plurality of groups or one part of the groups can be selected according to actual needs in practical application.

In the control, the point A is a transformer outgoing line point; the point B is an active compensation connection rear point; the point C is the point before the passive compensation TCR is connected, the SVC is a control target for zero reactive current and negative sequence current at the point B in the figure 5 by collecting voltage and current signals, and the closed-loop control is carried out on the reactive current of the load. And the APF in the active part is matched with the FC and the TSC in the SVC to carry out frequency division to suppress harmonic waves according to the collected harmonic current of the point C, and the selected harmonic current of the point C is used for filtering the harmonic waves of the load and the TCR, and simultaneously suppressing the parallel resonance caused by the FC and the TSC branch circuits and the power supply branch circuit, thereby improving the stability of the system. And SVG in the active part takes the voltage of A point as a control target, and controls transient voltage by changing reactive current injected into a power grid to inhibit flicker.

The current type harmonic source generated by the load can be regarded as an ideal harmonic current source and a parallel circuit with a large harmonic impedance, and the thyristor controlled reactor TCR can be equivalent to be composed of a nonlinear variable impedance and a harmonic current source through mathematical analysis, as shown in the PMAPPQC single-phase equivalent model of FIG. 6. Wherein

Is the voltage of the system power supply and,

、

、

、

、

respectively, the impedance of the power grid, the impedance of the nonlinear load, the impedance of the FC branch circuit, the impedance of the TSC branch circuit and the equivalent variable impedance of the TCR.

A source of harmonic current generated for the load,is a harmonic current source of the TCR, and the active compensation portion is assumed to be an ideal controlled current sourceThe other electrical quantities are defined as shown in the figure, but only by using

Andrepresenting the harmonic component and the fundamental component of the respective quantities, respectively.

As can be seen from FIG. 6, when only the fundamental current is considered, only the control angle of the variable TCR is needed to change its current

To control the reactive current at point B, i.e. to eliminate load currentReactive and negative sequence currents in; by controllingReactive current inThe residual reactive current after SVC compensation can be obtained by component, so that the bus currentNo reactive current is contained. When only harmonics are considered, only harmonics need to be considered

Harmonic current ofThe component makes it filter out part of harmonic current in C point, namely, characteristic subharmonic not containing FC and TSC tuned in operation

So that point C contains

Without other harmonics, andto be covered

And

filtered out to make the bus currentNo harmonic currents are contained. Wherein,

it is the harmonics that the FC and TSC will filter out, i.e.

＝

＋Thus, the APF and FC, TSC will not filter out the same order harmonics, preventing coupling.

Because the steady-state reactive power in the system is compensated by the SVC, the SVG only compensates the reactive power needed in the voltage transient process. Thus, the capacity of the SVC is the average reactive power of the measured load without compensation, while the capacity of the SVG is the average reactive power subtracted from the 95% probability maximum of the load fluctuating reactive power. This is calculated with a target reactive compensation rate of 95%, and with a response time of 5ms for SVG, the flicker improvement rate of the whole system will approach 80%. In order to reduce the capacity of SVG, the capacity thereof may also be determined according to the flicker improvement rate actually required.

In FIG. 6, let the voltage at point B, C beSince the functions of the parts of the PMAPPQC are different, the control of the PMAPPQC is naturally divided into three parts, namely SVC, APF and SVG, as shown in fig. 7. The SVC control module comprises a B point split-phase reactive power calculation module 1, a proportional integral module I2, a TSC switching control module 3, a phase control angle calculation module 4, a voltage

And current i_BInputting a B point split-phase reactive power calculation module 1, obtaining TSC switching control signals through a proportional-integral module I2 and a TSC switching control module 3, and entering each phase control angle calculation module 4 according to reactive power required to be generated by the TCR to obtain split-phase control signals of the TCR; the APF control module of the active power filter comprises a reactive harmonic compensation judgment module 5, a target harmonic detection module 6, a harmonic and direct current voltage PI regulation module 7 and a voltage

And current i_BThe input reactive harmonic compensation judgment module 5 calculates a target harmonic to be compensated, outputs the target harmonic obtained through calculation, performs proportional integral control with the transmitted harmonic input harmonic and the direct current voltage PI regulation module 7, determines a reference voltage, and generates a pulse to trigger each heavy module in the active power filter APF by comparing the reference voltage with a fixed triangular wave; the SVG control module comprises an adaptive fuzzy controller 8, a reactive current direct calculation module 9 and an instantaneous power balance-based double-closed-loop PI control module 10, wherein the instantaneous power balance-based double-closed-loop PI control module 10 outputs information according to the adaptive fuzzy controller 8 and the reactive current direct calculation module 9And obtaining a control signal of the SVG.

The specific control process is as follows: and the SVC device performs PI control on the reactive power of the point B, and adopts split-phase control on TCR and switching control on TSC. And APF is first based on

The degree of the voltage effective value deviating from the target voltage, if the voltage deviation degree is more than 15%, directly sending full reactive power to support the voltage so as to make up the deficiency of the SVG capacity; and if the voltage deviation degree is not more than 15%, determining a target harmonic needing to be compensated by combining the FC and the TSC which are currently running, dividing the frequency with the FC and the TSC to suppress the harmonic, and eliminating coupling. And carrying out PI control on the calculated target harmonic and the emitted harmonic, distributing according to the parallel multiples, carrying out PI control on the direct-current side voltage of the target harmonic and the emitted harmonic, determining a reference voltage, and comparing the reference voltage with a fixed triangular wave to generate a pulse to trigger each multiple module in the APF. For SVG, the voltage at point A is directly taken as a control target, or the reactive component of the current at point A is taken as a control target, and in order to improve the response speed and the system stability, a double-closed-loop voltage control strategy based on self-adaptive fuzzy control and instantaneous power balance and an instantaneous power balance double-closed-loop control strategy based on instantaneous reactive current PI control are applied.

In order to stabilize the access point voltage by using a static var generator, the most common control method is a double closed-loop method, the control method has good robustness, the defects are that 4 PI regulators are required to be designed, active current and reactive current are decoupled and controlled by using PI control, and parameters are difficult to determine in practical application. The document four new STATCOM voltage control method applied to an unbalanced system starts from an instantaneous power balance principle, and derives a conversion relation from output current to output voltage of an inverter, so that a current inner loop PI regulator in a double closed loop is omitted, but the method needs to know the equivalent resistance and the inductance value of an SVG device, and the two parameters are generally difficult to accurately measure and need to be corrected online. Furthermore, there is no current inner loop control, resulting in no consideration of inverter deathThe region or the like affects the dc side charging or the like, so that the voltage fluctuation on the dc side is large, and the control accuracy of the reactive current is low. The specific implementation mode of the invention integrates the advantages of the two methods, realizes active and reactive current decoupling and current-to-voltage conversion easily based on instantaneous power balance, and reduces the complexity of singly using a double closed loop design. Meanwhile, the double closed loop formed by the voltage inner loop and the current inner loop can make up the defect of inaccuracy of the equivalent resistance and the equivalent inductance value, as shown in fig. 3. Meanwhile, considering that a direct current capacitor is a relatively stable control object, a common PI controller can meet requirements, the voltage of a power grid is limited by multiple factors such as the power grid, loads, compensation and the like, the control parameters of the common PI regulation pass through tests and compromise between a transient state process and a steady state process to achieve a satisfactory effect, and the control effect of the PI regulation under large disturbance or small disturbance is obviously influenced. The adaptive fuzzy control is one of intelligent control, and the adaptive fuzzy control can effectively control under wider system operation conditions without knowing system information and a numerical sequence model thereof, so that the robustness of the system is improved. Therefore, the specific embodiment of the invention adopts the power grid voltage control based on the adaptive fuzzy control, and the power grid voltage control and the direct-current side voltage PI control form the voltage outer loop control in the double closed-loop system. As shown in fig. 7 and 8, the hybrid power quality management apparatus includes: the SVG double closed-loop voltage control module based on the self-adaptive fuzzy control and the instantaneous power balance comprises a current inner loop, a voltage outer loop and a current-voltage conversion module based on the instantaneous power balance, and outputs current i_cFed back to the current inner loop, phase e of a_aTwo output signals from a voltage outer ring, including one output signal from the adaptive fuzzy controller 8, enter a current inner ring through a phase locking module 22 and a sine-cosine conversion module 23, are subjected to difference operation with two output signals from the current inner ring through a first amplitude limiting module group 11, the output difference value enters a current pressure conversion module based on instantaneous power balance after passing through a first PI adjusting module group 12 and a second amplitude limiting module group 13, and the current pressure conversion module based on instantaneous power balance outputs a signal to a coordinate conversion module through calculationAnd a second module 16.

The specific control process is as follows:

(1) by detecting the DC side voltage at time k

After low-pass filtering with 130HZ cut-off frequency, the voltage is compared with the target voltage

After comparison, the process variable of the active current is obtained through PI regulation and amplitude limiting

(ii) a Simultaneously detecting VSI (Voltage Source Inverter) output current at k time

The base wave active current is obtained after dq conversion and low-pass filtering with the cutoff frequency of 25HZ respectively

And reactive current

. Will be provided with

Andthe difference is subjected to PI regulation and amplitude limiting to obtain active current to be sent at the k +1 moment

；

(2) By detecting the grid phase voltage at time k

Instantaneous value of target voltage obtained from target voltage and phase lock

Comparing, and obtaining the process variable of the reactive current after the adjustment and amplitude limiting of the adaptive fuzzy controller

(ii) a Simultaneous detection of VSI (voltage source inverter) output fundamental wave reactive current at time k. Will be provided with

Andthe difference is subjected to PI regulation and amplitude limiting to obtain reactive current to be sent at the k +1 moment

；

(3) Activating the target

And reactive current

By connecting equivalent reactance

And equivalents

The conversion of current into voltage is carried out according to the formula (1), wherein

To connect reactance values, an

Bad measurements were taken with the experimental value being 20% of the value of the connecting reactance. Selecting the d axis of the synchronous rotating coordinate system to coincide with the voltage vector of the access point, and setting the mode of the voltage vector as

. It is worth noting that

In practical application, the actual value is not necessarily the true value, but the coefficient of the PI is changed for correction;

(4) the obtained voltage variable under dq coordinate

And

obtaining reference signals of each phase voltage through dq inverse transformation

And comparing the signal with the triangular wave to obtain the trigger signal of each phase module. For N-fold modules, only the reactive current process variable obtained through adaptive fuzzy control is needed

N is equally divided, and corresponding triangular waves are subjected to 180 DEG/N phase shift to obtain respective trigger pulses.

The adaptive fuzzy controller 8 comprises in particular a fuzzy controller 17 and a neural network predictor 18, the fuzzy controller17 is input by bus voltage

Difference from target voltage

And

output as the change amount of the target reactive current

The neural network predictor 18 compares the voltage difference according to the K, K-1 and K-2 time points

And the actual amount of output reactive current

Predicting the bus voltage difference at the moment K +1

Thereby adjusting the regularity factor of the fuzzy controller 17. When the SVG takes the stable access point voltage as a control target, the difference of the access point voltage is taken as

Reciprocal of sum voltage difference

Fuzzy control is carried out for input quantity, and voltage difference of next moment is predicted by neural network model

And adjusting the corresponding fuzzy rule to improve the tracking speed and robustness of the controller. Wherein the neural network model is acquiredAnd

and determining corresponding coefficients by utilizing three-layer BP (Back Propagation) network training. As shown in fig. 9, whereinRepresents a delay of one sample time, and

is the output reactive current. The specific control flow is as follows:

(1) by collecting bus voltage at time K

And comparing the voltage difference with a target voltage to obtain a voltage difference

And combined with the last time voltage difference

Obtaining the rate of change of the voltage difference

These two variables serve as input variables for the fuzzy controller. Variation of target reactive current as output quantity

；

(2) The fuzzy controller can obtain the compensation difference at the K moment according to the input variable at the K moment and the corresponding fuzzy rule

Wherein, the Mamdani fuzzy inference method is adopted for inference, and the fuzzy solution method adopts a central area method;

(3) the neural network predictor is used for predicting the voltage difference according to K, K-1 and K-2 moments

And the actual amount of output reactive current

Predicting the bus voltage difference at the moment K +1

So as to adjust the regular coefficient of the fuzzy controller, and the fuzzy controller can output the difference value of the reactive current required at the moment of K +1

And time compensation, reducing the actual bus voltage difference at the K +1 th moment

. The training data of the neural network predictor is obtained by predicting the training data without the neural network in the fuzzy controller.

SVG is sometimes used for controlling the voltage stability of an access point, but due to the limit of SVG capacity, voltage drop caused by active current or voltage fluctuation caused by excessive reactive shock on a line cannot be suppressed by the SVG. Moreover, power factors are mainly considered in some occasions, so that the SVG takes the power factor of an access point as a control target in some occasions, namely, the reactive current of the access point is controlled. For example, the reactive current at point a in fig. 7 is the minimum, and the reactive current is obtained by collecting the current at point a and decomposing the active and reactive currents by using the instantaneous reactive theory. Because the SVG access point is behind the point A, the point AThe current emitted by the SVG is included in the current, so that a closed loop is naturally formed for controlling the reactive current at the point a, the target reactive current amount to be emitted by the SVG is obtained through PI regulation of the reactive current at the point a, and then, in combination with the double closed-loop control strategy based on instantaneous power balance, the double closed-loop control of the reactive current is performed as described in the SVG double closed-loop voltage control method based on adaptive fuzzy control and instantaneous power balance, as shown in fig. 10. The mixed power quality treatment device comprises: the double closed-loop control module for instantaneous power balance based on instantaneous reactive current PI control comprises a current inner loop, a voltage outer loop and a current-voltage conversion module based on instantaneous power balance, and outputs current i_cFed back to the current inner loop, phase e of a_aAfter passing through the phase locking module 22 and the sine-cosine conversion module 23, one path enters the current inner loop, and the other path is connected with the current i_a，i_b，i_cThe current-voltage-difference-based current-voltage conversion method comprises the steps of entering a coordinate conversion module I19, passing through a low-pass filter bank I20 and a PI controller I21, passing through a limiting module group I11 with another path of output signals from a voltage outer ring, respectively performing difference operation with two paths of output signals from a current inner ring, passing through a PI adjusting module group I12 and a limiting module group II 13 with output difference values, entering an instantaneous-power-based balance current-voltage conversion module, and calculating output signals to a coordinate conversion module II 16 based on the instantaneous-power-based balance current-voltage conversion module.

The specific control process is as follows:

(1) by detecting the DC side voltage at time k

After a low-pass filtering with a cut-off frequency of 130HZ, the voltage is compared with a target voltage

(ii) a Simultaneous detection of inverter output current at time k

The base wave active current is obtained after dq conversion and low-pass filtering to the cutoff frequency of 25HZ respectively

And reactive current

. Will be provided withAnd

after PI regulation and amplitude limiting are carried out on the difference, the active current to be sent at the k +1 moment is obtained

；

(2) The corresponding is obtained by phase locking the detection of the network voltage

And detecting the grid current at the time k

Performing coordinate transformation, namely transforming from abc coordinate to dq coordinate to obtain active current

And reactive current

And obtaining fundamental wave active current after low-pass filtering with cutoff frequency of 25HZ respectivelyAnd do not haveWork current

. To fundamental wave reactive currentCarrying out PI regulation and amplitude limiting to obtain target reactive current required to be sent

(ii) a Method for simultaneously detecting output fundamental wave reactive current of inverter at k time. Will be provided with

And

after PI regulation and amplitude limiting are carried out on the difference, the reactive current to be sent at the k +1 moment is obtained

；

(3) Activating the target

And reactive currentBy connecting equivalent reactance

And equivalents

The conversion of current into voltage is carried out according to equation (2), where

To connect reactance values, an

；

(4) The obtained voltage variable under dq coordinate

And

And comparing the signal with the triangular wave to obtain the trigger signal of each phase module. For N-fold modules, only the reactive current process variable obtained through adaptive fuzzy control is neededAnd N is equally divided, and the corresponding triangular wave is subjected to 180 DEG/N phase shift to obtain respective trigger pulse.

The SVG double closed-loop control of instantaneous power balance adopted by the specific implementation mode of the invention combines the advantages of the instantaneous power balance direct control and the traditional double closed-loop control. In this way, because a current feedback link is utilized, the sensitivity of the system to two values, namely equivalent resistance and equivalent inductance, is reduced, namely, the robustness of the whole system is enhanced by adding a current inner loop PI (Proportional-Integral) adjustment. Compared with the traditional double closed loop PI control, the double PI regulation is not needed to decouple active current and reactive current and realize the conversion from current to voltage, but the equivalent resistance and the equivalent inductance are added for calculation to directly convert the reference current into the reference voltage, so the calculation is simple and easy to realize, and the PI parameter of the whole system is easy to obtain.

The hybrid power quality management device further comprises: a PWM module 14, the PWM module 14 is a sine pulse width modulation module, and a second coordinate conversion module 16 outputs signals

And after the comparison with the triangular wave through the PWM module 14, the trigger signal of each phase module of the SVG is obtained and output to the voltage source inverter 15 to form a compensation current to compensate the electric energy quality of the load. And a module usually comprises 3 IGBT single bridges of a-phase, b-phase and c-phase. The method of modulating the modulated wave and the carrier wave uses an SPWM (Sinusoidal pulse width modulation) comparison generation method, and common SPWM comparison generation methods include a calculation method and a natural sampling method. In the embodiment of the present invention, a system configuration is adopted in which a DSP (Digital Signal Processing) calculates a modulated wave and an FPGA (Field Programmable Gate Array) modulates the modulated wave to generate an SPWM. Because the FPGA has the advantages of high operating frequency and capability of operating a plurality of modules in parallel, the specific implementation mode of the invention adopts the simplest and most convenient modulation mode of natural sampling.

However, when the natural comparison method is adopted in the FPGA, since the modulated wave and the carrier signal are both digital signals, and since the update frequencies of the two are different, there is a possibility that a plurality of comparisons occur at the intersection point at the time of comparison, as shown in fig. 11 and 12. When the modulation wave is updated at the place where it intersects with the carrier signal, multiple inversions of the PWM pulse will inevitably occur, thereby generating a narrow pulse which is extremely harmful. If the narrow pulse is too short, the device is not completely closed and turned on again or is not completely turned on and then is turned off, and the safe operation of the device and the normal operation of a system are threatened. Aiming at the situation, the specific implementation mode of the invention adopts a novel natural comparison mechanism, and can effectively eliminate the narrow pulse.

Since the above-mentioned narrow pulses are caused by multiple comparisons of the modulated wave with the carrier wave, the embodiment of the present invention designs a pulse inversion locking mechanism and a corresponding narrow pulse cancellation module as shown in fig. 13 below. The locking signal of the narrow Pulse cancellation module locking mechanism is a turning signal of each phase of IGBT trigger signal, that is, a turning signal of PWM (Pulse-width modulation), and the unlocking signal is a peak and a trough of a carrier. And when the modulated wave and the carrier wave are compared at the intersection point and are turned over, immediately locking, and forbidding the PWM signal from turning over before unlocking. Therefore, multiple times of turning of the PWM at the intersection point is avoided, and narrow pulses are eliminated.

With this locking mechanism, the narrow pulses are significantly eliminated, and fig. 14 and 15 are waveform comparisons, respectively, before the locking mechanism is used. Before locking, the line voltage PWM output will have a negative going pulse where it should be a positive going pulse, or a positive going pulse where it should be, due to the presence of the narrow pulse. This phenomenon is clearly observed in fig. 14, which is effectively prevented in fig. 15 after the locking mechanism is employed.

In the aspect of reactive power compensation, SVG is used for compensating the difference between SVC compensation and reactive power needed to be compensated by a target, so that the SVG does not operate at full load at most of time. Particularly, only a small amount of reactive power needs to be compensated, but more harmonics exist. Therefore, at the moment, the SVG can improve the switching frequency, compensate small amount of reactive power and filter system harmonic waves at the same time. In which the harmonics pass through the conventional i_p－i_qThe harmonic voltage component obtained by the calculation and the adjustment is superposed on the harmonic voltage components in the graphs of FIG. 9 and FIG. 11

And (4) performing neutralization. But because the switching device is subject to heat dissipationEtc., the higher the switching frequency, the less current that is allowed to pass, and the need to change the frequency of the switching device in order to switch between emitting different reactive and harmonic currents. The frequency change is mainly determined by the reactive power to be emitted by the SVG, and the reactive power to be emitted by the SVG can be estimated from the previous power frequency period, so that the switching frequency value of a device in the next period can be changed according to the reactive power required to be emitted by the SVG in the next period, and the peak value of the reactive current allowed to be emitted by the SVG is changed, so that the device can be protected from overcurrent and overvoltage. Wherein the conversion of the frequency of the switching device is performed by periodically changing the frequency of the carrier wave (triangular wave) with reference to the synchronous voltage. The frequency is determined according to the characteristics of the device and the required capacity, and corresponding rules can be formulated according to the device and the turn-off overvoltage condition of the device. For example, when the SIIP2403GB172 module is used, the effective value of reactive current required to be compensated is assumed to be

With a switching frequency of

The maximum instantaneous current allowed to pass is

Then, the following initial rules can be established:

Ⅰ、IF

THEN

AND

；

Ⅱ、IF

THEN

AND

；

Ⅲ、IF

THEN

AND

；

Ⅳ、IF

THEN AND

；

Ⅴ、IF

THEN

AND

。

the hybrid compensation mode takes advantages of various compensation devices, and achieves an effect equivalent to large-capacity active compensation by using the active part with smaller capacity. The mode of combining the multiple compensators has the advantages of distributed control, small coupling, easy realization and no shutdown of the whole device caused by the failure of one device. In addition, the method has the advantages of low cost, mature technology and good stability.

By applying the hybrid power quality management device described by the embodiment of the invention, the following technical effects can be achieved:

1. the SVG capacity in the SVG and SVC combination subtracts the average reactive power according to the 95% probability maximum value of the load fluctuation reactive power, so that the minimization of the SVG capacity can be realized, and the cost is reduced;

2. compared with the traditional double closed loops, the SVG double closed loop voltage control technology based on instantaneous power balance has the advantages that the PI parameter setting of the controller is simpler;

3. the voltage adaptive fuzzy control enables the robustness of the voltage control of the access point to be good, and the compensation effect on voltage fluctuation is improved;

4. the narrow pulse suppression technology is simple and practical, and compared with a method for greatly improving the carrier amplitude or adopting narrow pulse filtering, the method is simple and reliable;

5. the SVG harmonic suppression technology based on carrier frequency conversion is particularly useful for some occasions without APF, fully utilizes active functions, and is a strategy with priority on reactive power compensation and consideration on harmonic suppression. The switching frequency of the device is improved through carrier frequency conversion, and the method is simple, practical and reliable.

It should be noted that a part of the basic functions of the embodiment of the present invention can be achieved by a method of performing large-capacity compensation directly using large-capacity SVG or APF and simultaneously suppressing reactive power, harmonics, and negative-sequence current, but such a required capacity is large. APF is difficult to achieve such a capacity as several tens of megabits, whereas SVG can achieve such a large capacity by cascade connection or the like, but as the capacity increases, the cost price increases by several times, and the stability performance decreases.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.

Claims

1. A hybrid power quality management device, comprising: the active part comprises an active power filter APF and a static var generator SVG, wherein the static var generator SVG is mainly used for providing transient reactive power, and the active power filter APF is used for filtering harmonic waves; the active power filter APF and the static var generator SVG are not less than two groups and are connected with a three-phase power grid in a parallel connection mode in a transformer isolation mode; the passive part comprises a Static Var Compensator (SVC) which is used for providing steady-state reactive power; the static var compensator SVC comprises a thyristor switched capacitor TSC, a thyristor controlled reactor TCR, a fixed capacitance compensation FC, a thyristor switched capacitor TSC, a thyristor controlled reactor TCR and a fixed capacitance compensation FC which are all directly connected with a three-phase power grid; the thyristor switched capacitor TSC is used for providing high-capacity capacitive reactive power, the fixed capacitor compensation FC is used for providing low-capacity reactive power, and the fixed capacitor compensation FC is also used as a main subharmonic filtering branch of the thyristor controlled reactor TCR.

2. A hybrid power quality management device according to claim 1, wherein the hybrid power quality management device comprises: the SVC control module comprises a B point split-phase reactive power calculation module (1), a first proportional-integral module (2), a TSC switching control module (3), a control angle calculation module (4) of each phase, a voltage

And current i_BAnd the phase-splitting reactive power calculation module (1) of the point B is input, TSC switching control signals are obtained through the proportional-integral module I (2) and the TSC switching control module (3), and the phase-splitting control signals of the TCR are obtained through entering the phase control angle calculation module (4) according to reactive power required to be generated by the TCR.

3. A hybrid power quality management device according to claim 2, wherein the hybrid power quality management device comprises: the active power filter APF control module comprises a reactive harmonic compensation judgment module (5), a target harmonic detection module (6), a harmonic and direct current voltage PI regulation module (7) and a voltage

And current i_BInput reactive harmonic compensation judgment module(5) The reactive harmonic compensation judgment module (5) calculates a target harmonic needing to be compensated, outputs the target harmonic obtained through calculation, performs proportional-integral control with the transmitted harmonic input harmonic and the direct-current voltage PI regulation module (7), determines a reference voltage, and compares the reference voltage with a fixed triangular wave to generate a pulse to trigger each heavy module in the active power filter APF.

4. A hybrid power quality management device according to any one of claims 1, 2 and 3, wherein the hybrid power quality management device comprises: the SVG control module comprises an adaptive fuzzy controller (8), a reactive current direct calculation module (9) and an instantaneous power balance-based double-closed-loop PI control module (10), wherein the instantaneous power balance-based double-closed-loop PI control module (10) obtains a control signal of the SVG according to output signals of the adaptive fuzzy controller (8) and the reactive current direct calculation module (9).

5. A hybrid power quality management device according to claim 4, wherein the hybrid power quality management device comprises: the SVG double closed-loop voltage control module based on the self-adaptive fuzzy control and the instantaneous power balance comprises a current inner loop, a voltage outer loop and a current-voltage conversion module based on the instantaneous power balance, and outputs current i_cFed back to the current inner loop, phase e of a_aThe current inner loop enters the current inner loop through a phase locking module (22) and a sine and cosine conversion module (23), two paths of output signals from a voltage outer loop including one path of output signals from an adaptive fuzzy controller (8) pass through a first amplitude limiting module group (11) to be respectively subjected to difference operation with two paths of output signals from the current inner loop, the output difference enters a current pressure conversion module based on instantaneous power balance after passing through a first PI adjusting module group (12) and a second amplitude limiting module group (13), and the current pressure conversion module based on the instantaneous power balanceAnd the constant flow pressure conversion module outputs the signals to the second coordinate conversion module (16) through calculation.

6. The hybrid power quality management device according to claim 5, wherein the adaptive fuzzy controller (8) comprises a fuzzy controller (17) and a neural network predictor (18), and the input of the fuzzy controller (17) is bus voltage

Figure 2010102756513100001DEST_PATH_IMAGE002

Difference from target voltage

And

Figure 2010102756513100001DEST_PATH_IMAGE004

output as the change amount of the target reactive current

Figure 2010102756513100001DEST_PATH_IMAGE006

The neural network predictor (18) is used for predicting the voltage difference according to K, K-1 and K-2 moments

And the actual amount of output reactive current

Predicting the bus voltage difference at the moment K +1

Thereby adjusting the regularity factor of the fuzzy controller (17).

7. A hybrid electrical energy mass as in claim 4The device is administered to volume, its characterized in that, mixed type electric energy quality administer the device and include: the double closed-loop control module for instantaneous power balance based on instantaneous reactive current PI control comprises a current inner loop, a voltage outer loop and a current-voltage conversion module based on instantaneous power balance, and outputs current i_cFed back to the current inner loop, phase e of a_aOne path enters a current inner ring after passing through a phase locking module (22) and a sine and cosine conversion module (23), and the other path is connected with a current i_a，i_b，i_cAnd the current difference value is subjected to difference value operation with the other path of output signals from the voltage outer ring through a first amplitude limiting module group (11) after passing through a first low-pass filter group (20) and a first PI controller (21), and then enters a current pressure conversion module based on instantaneous power balance, and the current pressure conversion module based on instantaneous power balance calculates output signals to a second coordinate conversion module (16) after passing through a first PI adjusting module group (12) and a second amplitude limiting module group (13).

8. A hybrid power quality management device according to claim 5 or 7, wherein the hybrid power quality management device comprises: the PWM module (14) is a sine pulse width modulation module, and the coordinate conversion module II (16) outputs signals

And after the triangular wave is compared with the triangular wave through the PWM module (14), the trigger signal of each phase module of the SVG is obtained and is output to the voltage source inverter (15) to form compensation current so as to compensate the electric energy quality of the load.

9. A hybrid power quality management device according to claim 5 or 7, wherein the sinusoidal pulse width modulation module comprises: and the narrow pulse eliminating module is used for locking a locking signal of each phase of IGBT trigger signal, namely a turning signal of the PWM module (14), and unlocking signals are wave crests and wave troughs of the carrier wave, and when the modulation wave and the carrier wave are compared at an intersection point and are turned over, the narrow pulse eliminating module immediately locks and forbids the PWM signal to be turned over before unlocking.

10. A hybrid power quality management device according to claim 5 or 7, wherein the hybrid power quality management device comprises: switching device frequency conversion module, switching device frequency conversion module links to each other with SVG for the frequency of switching device in sending different reactive current and the conversion change SVG between harmonic current is sent to change SVG, and change and allow SVG to send the peak value of reactive current, protection device does not overflow and overvoltage.