CN105720590A - Flexible control device and method for reactive compensation of distribution station area - Google Patents

Abstract

The invention relates to a flexible control device and method for reactive compensation of a distribution station area. The control device is composed of an operation control link that exchanges data by a high speed SPI bus and a communication and man-machine interaction link; and the control method provided by the invention comprises the steps of collecting a three-phase instantaneous voltage value and a current value of a distribution station area system to calculate and obtain active power, reactive power, a power factor and current unbalance degree, selecting a corresponding compensation control strategy according to the size of the current unbalance degree, converting a network combination structure of an existing active compensator capacitor bank to realize single reactive compensation or simultaneous reactive and three-phase load unbalance comprehensive compensation of the distribution station area. By adopting the flexible control device and method provided by the invention, the existing compensation network elements can be fully used, ''hardness is replaced by flexibility'', various load working conditions are applicable, the flexibility is good, the cost performance is good, and the single function defects of a conventional control device and method that only reactive compensation can be realized and that the three-phase load unbalance cannot be compensated.

Description

Power distribution station reactive-load compensation flexible control device and method

Technical field

The invention belongs to flexible AC distribution system or electric intelligent field of power distribution, relate to a kind of power distribution station reactive-load compensation flexible control device and control method thereof.

Background technology

The final link that power distribution station is sent as power system electric energy transmission & distribution, it is the pith of intelligent grid construction, its idle effective compensation that carries out can be improved the utilization rate of power distribution station transformator with control, reduce line voltage distribution loss and active loss, enhancing system safety in operation and economy.

Well known in the art at present the control of reactive power compensating strategy automatic switchings such as power factor method, reactive current or reactive power method, nine-area method are utilized to be arranged on the Shunt Capacitor Unit in the system of power distribution station, because having cost performance height, the maintainable advantage such as strong, it is still present stage extensive use and compensates the mainstream technology behave that power distribution station is idle.But in recent years, along with social development and progress, people's daily life often uses the irrational heavy power single-phase of spatial and temporal distributions, three-phase imbalance electrical loads in a large number, cause asymmetric (threephase load is uneven) problem that the properly functioning generation of platform district distribution system is day by day serious, cause the loss increase of distribution transformer and circuit, distribution transformer zero-sequence current to strengthen harm such as causing transformator local temperature overheating, electrical equipment safety in operation and electric energy metrical accuracy reduction.Obviously, to be only limitted to compensate power distribution station idle for above-mentioned known compensating control method, it is impossible to effectively solves three-phase load unbalance adjustment and compensation problem, there is function singleness, flexible poor defect.

Summary of the invention

The problems referred to above that it is an object of the invention to prior art is existed are solved, a kind of power distribution station reactive-load compensation flexible control device is provided, thering is provided a kind of power distribution station reactive-load compensation flexible control method adopting this control device, the available existing reactive-load compensation in the power distribution station element of the present invention realizes its idle separate compensation or idle and threephase load imbalance comprehensive compensation simultaneously Flexible Control simultaneously.

Technical scheme for realizing foregoing invention purpose is as described below.

A kind of power distribution station reactive-load compensation flexible control device, is made up of operation control link and communication and man-machine interaction link, between the two by high speed SPI bus exchanging data；

Operation control link includes again power distribution station system electric parameter detection and conditioning unit, key control unit and three master sheet units of output performance element, wherein:

Power distribution station system electric parameter and conditioning unit are by detecting voltage by three phase module, three-phase current detection module, switch closes a point state detection module, analog signal conditioner circuit module, on-off model conditioning circuit module forms, the outfan of detecting voltage by three phase module and three-phase current detection module accesses the input of No. 1 Single Chip Microcomputer (SCM) system module in key control unit after analog signal conditioner circuit module is nursed one's health, switch closes the outfan of point state detection module and processes, through on-off model conditioning circuit module, the input being followed by key control unit CPLD logical AND combined system module with isolation；

Key control unit is made up of No. 1 Single Chip Microcomputer (SCM) system module and CPLD logical AND combined system module, No. 1 Single Chip Microcomputer (SCM) system module is connected with CPLD logical AND combined system module by universal parallel I/O port, time actually used, by No. 1 one-chip computer module in power distribution station reactive-load compensation flexible control device complete electrical quantity read in real time, the realization of reactive-load compensation Flexible Control algorithm and compensate sending of control instruction；

Output performance element is outputed return circuit module by power photoelectric coupler module and reactive-load compensation and is formed, and in key control unit, the outfan of CPLD logical AND combined system module outputs the input of return circuit module by passing to reactive-load compensation after the isolation of power photoelectric coupler module；

Communication and man-machine interaction link include again man-machine interaction unit, computing and control processing unit and three master sheet units of communication unit, wherein:

Man-machine interaction unit is made up of Keysheet module, LCD MODULE, is being connected with No. 2 Single Chip Microcomputer (SCM) system modules in operation processing unit by universal parallel I/O port respectively after magnetic coupler module is isolated；

Computing is made up of No. 2 Single Chip Microcomputer (SCM) system modules with controlling processing unit, it is connected with No. 1 Single Chip Microcomputer (SCM) system module by high speed SPI bus, time actually used, by man-machine interaction and communication functions such as the setting of No. 2 one-chip computer module completion system parameters in power distribution station reactive-load compensation flexible control device, display storages；

Communication unit is made up of ethernet communication interface module, RS232 interface module, RS485 interface module, and sequentially embedded with No. 2 Single Chip Microcomputer (SCM) system modules controlled in processing unit with computing after magnetic coupler module is isolated respectively UART1, UART2 serial port of their outfan is connected.

In specific embodiments, in this device power distribution station system electric parameter detection and conditioning unit in detecting voltage by three phase module adopt three voltage transformers arranged side by side, three-phase current detection module adopt three current transformers arranged side by side；Switch closes the input of point state detection module directly from compensating each air switch QF in loop in the reactive compensation system of power distribution station_mThe auxiliary contact of (m=1,2,3,4), realize the stabilization modulate circuit being made up of clamp diode, amplitude limit stabilivolt, general capacitance resistance ware that the stabilization place reason on-off model conditioning circuit module of switch auxiliary contact is built-in；Reactive-load compensation in output performance element is outputed return circuit module and is adopted 12 control relays arranged side by side.

The power distribution station reactive-load compensation flexible control method adopting this control device includes following enforcement step:

One, the three-phase instantaneous voltage value u of power distribution station system is gathered respectively by the detecting voltage by three phase module (1) of power distribution station reactive-load compensation flexible control device and three-phase current detection module (2)_A(t)、u_B(t)、u_CThe three-phase instantaneous current value i of (t) and distribution transformer wire inlet loop_A(t)、i_B(t)、i_CT (), calculates defined formula according to known Instantaneous Power Theory and three-phase alternating current active power, reactive power, power factor and calculates acquisition power distribution station system three phases active power virtual value P, each phase active power virtual value P_A、P_B、P_C, three phase reactive power virtual value Q, each phase reactive power virtual value Q_A、Q_B、Q_C, three-phase activity coefficientAnd each phase power factorAnd be stored in No. 1 Single Chip Microcomputer (SCM) system module (6) in power distribution station reactive-load compensation flexible control device；According to the following equation (1) the three-phase current instantaneous value i to collecting_A(t)、i_B(t)、i_CT () makes symmetrical component transformation, obtain the zero sequence i of current time three-phase current₀, positive sequence i₁, negative sequence component i₂,

$\left[\begin{array}{c}{i}_0\\ i_1\\ i_2\end{array}\right]=\frac{1}{3}\left[\begin{array}{ccc}1& 1& 1\\ 1& \mathrm{\α}& {\mathrm{\α}}^2\\ 1& {\mathrm{\α}}^2& \mathrm{\α}\end{array}\right]\left[\begin{array}{c}{i}_A\left(t\right)\\ i_B\left(t\right)\\ i_A\left(t\right)\end{array}\right]---\left(1\right),$

Operator α=e in formula^j120°, calculate by following equation (2) afterwards and obtain the instantaneous negative phase-sequence degree of unbalancedness of electric current

${\mathrm{\ϵ}}_{I_2}=\frac{i_2}{i_1}---\left(2\right);$

Two, to calculate acquisitionIt is worth the foundation selecting different Compensation Strategies as power distribution station reactive-load compensation flexible control device, whenAutomatically the control of reactive power compensating strategy well known in the art is chosen during less than device default setting value 0.2, whenComprehensive compensation control strategy is then chosen, each meritorious mutually and reactive power P that namely will obtain by power distribution station reactive-load compensation flexible control device and store during be more than or equal to 0.2_A、P_B、P_C、Q_A、Q_B、Q_CSubstitute into following equation (3), ask for intermediate variable Q_xmin, Q in formula_x1、Q_x2、Q_x3、Q_x4、Q_x5、Q_x6It is intermediate variable, Q_xminMinima for these intermediate variables；

$\left\{\begin{array}{c}{Q}_{x1}<-\frac{4\sqrt{3}}{3}(P_C-P_B)-(-3Q_A+Q_B+Q_C)\\ Q_{x2}<-\frac{4\sqrt{3}}{3}(P_A-P_C)-(Q_A-3Q_B+Q_C)\\ Q_{x3}<-\frac{4\sqrt{3}}{3}(P_B-P_A)-(Q_A+Q_B-3Q_C)\\ Q_{x4}>\frac{8\sqrt{3}}{3}(P_B-P_A)-(Q_A+Q_B+Q_C)\\ Q_{x5}>\frac{8\sqrt{3}}{3}(P_C-P_B)-(Q_A+Q_B+Q_C)\\ Q_{x6}>\frac{8\sqrt{3}}{3}(P_A-P_C)-(Q_A+Q_B+Q_C)\\ Q_x=Q_{x\min }=\min \{Q_{x1},Q_{x2},Q_{x3},Q_{x4},Q_{x5},Q_{x6}\}\end{array}\right.---\left(3\right)$

If Q_xminThere is solution then to be substituted into formula (4), try to achieve Y wiring further respectively and compensate tank capacitors group ideal capacity valueTank capacitance group ideal capacity value is compensated with delta connection

$\left\{\begin{array}{c}{Q}_A^Y=\frac{\sqrt{3}}{3}(P_C-P_B)+\frac{1}{4}(-3Q_A+Q_B+Q_C)+\frac{1}{4}{Q}_{xmin}\\ Q_B^Y=\frac{\sqrt{3}}{3}(P_A-P_C)+\frac{1}{4}(Q_A-3Q_B+Q_C)+\frac{1}{4}{Q}_{xmin}\\ Q_C^Y=\frac{\sqrt{3}}{3}(P_B-P_A)+\frac{1}{4}(Q_A+Q_B-3Q_C)+\frac{1}{4}{Q}_{x\min }\\ Q_{AB}^{\mathrm{\&Delta;}}=\frac{2\sqrt{3}}{3}(P_B-P_A)-\frac{1}{4}(Q_A+Q_B+Q_C)-\frac{1}{4}{Q}_{x\min }\\ Q_{BC}^{\mathrm{\&Delta;}}=\frac{2\sqrt{3}}{3}(P_C-P_B)-\frac{1}{4}(Q_A+Q_B+Q_C)-\frac{1}{4}{Q}_{x\min }\\ Q_{CA}^{\mathrm{\&Delta;}}=\frac{2\sqrt{3}}{3}(P_A-P_C)-\frac{1}{4}(Q_A+Q_B+Q_C)-\frac{1}{4}{Q}_{x\min }\end{array}\right.---\left(4\right),$

If Q_xminThen press without solutionProcess less than 0.2 situation；

Three, reactive-load compensation flexible control device in power distribution station compensates algorithm computing online according to selected Compensation Strategies, and output switching instruction controls each the multiple control switch FK in the system of power distribution station_mn(m=1,2,3,4, n=1,2,3) conjunction/transfer is made to change the compound mode structure compensating Capacitor banks to carry out compensation accordingly: when the Compensation Strategies selected is for control strategy well known in the art, by multiple control switch FK_mnCapacitor banks is made to be configured to the common benefit of routine and divide a benefit compound mode to be incorporated to system, it is achieved the compensation to System Reactive Power；When the Compensation Strategies selected is comprehensive compensation control strategy, by multiple control switch FK_mnMake Capacitor banks be configured to Y wiring to compensate loop and delta connection and compensate loop combination mode, and bank capability value closest to ideal capacity valueCapacitor banks be incorporated to system, it is achieved to System Reactive Power with threephase load is unbalanced compensates simultaneously.

Compared with prior art, beneficial effects of the present invention is as described below.

(1), method of the present invention is applicable to the power distribution station (three-phase three-wire system load, three-phase four-wire system load, phase three-wire three mix load processed with three-phase four) of all kinds of load behaviors, integrating power distribution station reactive-load compensation to mend with threephase load imbalance tune, the scope of application is big, strong robustness.

(2), adopt the method for the present invention can according to the flexible automatic change Compensation Strategies of power distribution station self-operating operating mode, combinative structure by different control strategy varying capacitors groups, existing compensation network element can be made full use of, " hard with soft generation ", realize the idle separate compensation in power distribution station or idle unbalanced with threephase load compensate simultaneously, it is flexible, cost performance is high, practical value is notable, it is suitable for all kinds of load behaviors, what effectively overcome conventional control methods existence is only capable of compensating reactive power, the function singleness defect mending three-phase imbalance load can not be adjusted.

(3), apparatus of the present invention adopt dual processors (two Single Chip Microcomputer (SCM) system modules) structure, functional areas are obvious, it is easy to upgrading, arrange proprietary communication and man-machine interaction link, directly seamless can incorporate intelligent power distribution platform district control platform.

Accompanying drawing explanation

Accompanying drawing 1 is the major loop schematic diagram of power distribution station reactive compensation system.

Accompanying drawing 2 is the circuit theory diagrams of reactive-load compensation flexible control device in power distribution station of the present invention.

In accompanying drawing 2, each label title is respectively as follows: I-operation control link, II-communication and man-machine interaction link, III-transformator (inlet wire) loop, IV-reactive-load compensation loop (3 road △ compensate+1 road Y and compensate), V-loop occurs；The I system electric parameter detection of-A-power distribution station and conditioning unit, I-B-key control unit, I-C-exports performance element, II-A-man-machine interaction unit, II-B-computing and control processing unit, II-C-communication unit；1-detecting voltage by three phase module (voltage transformer), 2-three-phase current detection module (current transformer), 3-switch closes a point state detection module, 4-analog signal conditioner circuit module, 5-on-off model conditioning circuit module, 6-1 Single Chip Microcomputer (SCM) system module, 7-CPLD logical AND combined system module, 8-power photoelectric coupler module, return circuit module is outputed in 9-reactive-load compensation, 10-Keysheet module, 11-LCD MODULE, 12-magnetic coupler module, 13-magnetic coupler module, 14-2 Single Chip Microcomputer (SCM) system module, 15-magnetic coupler module, 16-magnetic coupler module, 17-magnetic coupler module, 18-ethernet communication interface module, 19-RS232 interface module, 20-RS485 interface module.

Detailed description of the invention

Below in conjunction with accompanying drawing, present invention is described further.

As shown in Figure 1, power distribution station system adopts three-phase four-wire power supply mode, and containing phase three-wire three, three-phase and four-line load, the idle compensation loop with three-phase load unbalance is compensated loop by delta connection and collectively constitutes with Y wiring compensation loop.

As shown in Figure 2, it is made up of a kind of example structure of reactive-load compensation flexible control device in power distribution station of the present invention operation control link I and communication and man-machine interaction link II, carries out data exchange by high speed SPI bus between two parts.

Operation control link I is made up of the detection of power distribution station system electric parameter and conditioning unit I-A, key control unit I-B and output performance element I-C three part, and the detection of power distribution station system electric parameter and conditioning unit I-A, output performance element I-C are connected with key control unit I-B respectively through the corresponding interface.

Power distribution station system electric parameter detection and conditioning unit I-A are closed a point state detection module 3, analog signals conditioning circuit module 4 and on-off model conditioning circuit module 5 formed by detecting voltage by three phase module 1, three-phase current detection module 2, switches.Detecting voltage by three phase module 1 is connected with analog signal conditioner circuit module 4 respectively with the output of three-phase current detection module 2, and switch closes the outfan of point state detection module 3 and isolates the CPLD logical AND combined system module 7 being followed by key control unit I-B through on-off model conditioning circuit module 5.During work, the three-phase voltage of power distribution station system sends into detecting voltage by three phase module 1, three-phase current by sending into three-phase current detection module 2 after existing current transformer conversion by the directly mode of adopting, and obtains power distribution station system instantaneous voltage value u after analog signal conditioner circuit module 4 processes_A(t)、u_B(t)、u_C(t) and instantaneous current value i_A(t)、i_B(t)、i_C(t)；Power distribution station system air switch QF_mAuxiliary contact signal be directly accessed switch and close a point state detection module 3.In the structural design of instantiation, detecting voltage by three phase module 1 adopts three voltage transformers arranged side by side (such as HPT304A, HRPT-1), three-phase current detection module 2 adopts three current transformers arranged side by side (such as HCT255A, HRCT-1), analog signal conditioner circuit module 4 is changed by I/V and amplifying circuit is (such as RVC420, LM324 and peripheral auxiliary element), clamp diode (such as IN4148), amplitude limit stabilivolt, the wave filter of general capacitance resistance ware composition realizes, switch closes the isolation circuit realiration that point state detection module 3 is made up of Universal photoelectric bonder (such as TLP521-X), on-off model conditioning circuit module 5 adopts by clamp diode (such as IN4001), amplitude limit stabilivolt, the typical amplitude limit that general capacitance resistance ware is constituted, Anti-shaking circuit realizes.

Key control unit I-B is made up of No. 1 Single Chip Microcomputer (SCM) system module 6, CPLD logical AND combined system module 7.No. 1 Single Chip Microcomputer (SCM) system module 6 is connected by universal parallel I/O port with CPLD logical AND combined system module 7 and carries out data exchange with it.In instantiation structural design, No. 1 Single Chip Microcomputer (SCM) system module 6 can adopt the digital signal processor (such as Dspic30F6014A) of built-in multi-channel A/D, and CPLD logical AND combined system module 8 adopts MAX7000 family device (such as EPM7128).

Output performance element I-C is mainly outputed return circuit module 9 by reactive-load compensation and forms, and is connected with the outfan of CPLD logical AND combined system module 7 in key control unit I-B after being isolated by power photoelectric coupler module 8.It is embodied as in structure, reactive-load compensation is outputed loop 9 and is adopted 12 general controls relays (such as JQX-14) arranged side by side or solid-state relay SSR (such as S310ZK), and power photoelectric coupler module 8 adopts the optocoupler (such as TLP127) that 12 driving forces arranged side by side are bigger.

Communication and man-machine interaction link II are made up of man-machine interaction unit II-A, computing and control processing unit II-B and communication unit II-C three part, and man-machine interaction unit II-A, communication unit II-C are connected with controlling processing unit II-B with computing respectively through the corresponding interface.

Man-machine interaction unit II-A is made up of Keysheet module 10, LCD MODULE 11, is being connected with controlling No. 2 Single Chip Microcomputer (SCM) system modules 14 in processing unit II-B with computing by universal parallel I/O port respectively after two magnetic coupler modules 12,13 are isolated.Instantiation is implemented in structure, LCD MODULE 11 adopts general LCD (such as LM3033, LM6066, NS12864), Keysheet module 10 adopts general Independent keys, and two magnetic coupler modules 12,13 need to select high speed magnetic isolating device (such as ADUM1200).

Computing is made up of No. 2 Single Chip Microcomputer (SCM) system modules 14 with controlling processing unit II-B, and being connected with No. 1 one-chip computer module 6 by high speed SPI bus carries out data exchange.In instantiation structural design, No. 2 Single Chip Microcomputer (SCM) system modules adopt the single-chip microcomputer (such as Dspic30F6014A) with built-in multichannel universal serial port (UART).

Communication unit II-C is mainly made up of ethernet interface module 18, RS232 interface module 19, RS485 interface module 20, processes the UART bus of No. 2 Single Chip Microcomputer (SCM) system modules 14 in II-B with computing with control respectively and be connected after three magnetic coupler modules 15,16,17 are isolated.Ethernet interface module 12 can be made up of 18F66J60, HR911105A device or directly select Ethernet special module (such as HV2002D-TX), RS232 interface module 19 selects integrated interface chip (such as MAX232), RS485 interface module 20 selects integrated interface chip (such as MAX485), and three magnetic coupler modules 15,16,17 need to select high speed magnetic isolating device (such as ADUM1200).

The substance of reactive-load compensation flexible control method in power distribution station of the present invention is by the detecting voltage by three phase module 1 of power distribution station reactive-load compensation flexible control device, three-phase current detection module 2, the three-phase current of the three-phase voltage of power distribution station system, distribution transformer (inlet wire) loop to be sampled, amplify through analog signal conditioner circuit module 4, amplitude limit, filtering, I/V conversion after, send into No. 1 Single Chip Microcomputer (SCM) system module 6 containing built-in A/D converter to calculate, analyze, process and record, obtain corresponding instantaneous voltage value u_A(t)、u_B(t)、u_CThe instantaneous current value i in (t) and distribution transformer (inlet wire) loop_A(t)、i_B(t)、i_CT (), is calculated and stores obtained power distribution station system three phases active power virtual value P, each phase active power virtual value P according to known Instantaneous Power Theory and three-phase alternating current active power, reactive power, power factor defined formula by No. 1 Single Chip Microcomputer (SCM) system module 6_A、P_B、P_C, three phase reactive power virtual value Q, each phase reactive power virtual value Q_A、Q_B、Q_C, three-phase activity coefficientEach phase power factorFormula (1) in saving further according to foregoing summary, (2) calculate and obtain the instantaneous negative phase-sequence degree of unbalancedness of electric currentTo calculate acquisitionIt is worth the foundation selecting different Compensation Strategies as power distribution station reactive-load compensation flexible control device, whenAutomatically conventional the control of reactive power compensating strategy is chosen during less than 0.2 (default setting value), whenComprehensive compensation control strategy is then chosen, each meritorious mutually and reactive power P that namely will obtain by No. 1 Single Chip Microcomputer (SCM) system module 6 and store during be more than or equal to 0.2_A、P_B、P_C、Q_A、Q_B、Q_CSubstitute into the formula (3) of foregoing summary joint, (4), try to achieve Y wiring and compensate tank capacitors group ideal capacity valueTank capacitance group ideal capacity value is compensated with delta connection(then press without when solvingProcess less than 0.2 situation)；No. 1 Single Chip Microcomputer (SCM) system module 6 is according to selected Compensation Strategies output switching instruction, send into CPLD logical AND combined system module 7 and carry out logical operations, through power photoelectric coupler module 8 isolation with drive, then deliver to reactive-load compensation output return circuit module 9 controls further in the system of power distribution station multiple control switch FK_mn(m=1,2,3,4, n=1,2,3) conjunction/transfer is made to change the compound mode structure compensating Capacitor banks to carry out compensation accordingly: when the Compensation Strategies selected is for control strategy well known in the art, multiple control switch FK_mnCapacitor banks can be made to be configured to the common benefit of routine and divide a benefit compound mode to be incorporated to system, only realize the compensation to System Reactive Power；When the Compensation Strategies selected is comprehensive compensation control strategy, multiple control switch FK_mnCapacitor banks can be made to be configured to Y wiring compensate loop and delta connection and compensate loop combination mode, bank capability value closest to ideal capacity valueThe Capacitor banks of value is incorporated to system, it is achieved to System Reactive Power and threephase load unbalanced while comprehensive compensation.

In real work, communication in this power distribution station reactive-load compensation flexible control device and man-machine interaction link II are for man-machine interaction and communication functions such as the setting of completion system parameter, display storages, wherein, computing accepts to produce key information from Keysheet module 10 with No. 2 Single Chip Microcomputer (SCM) system modules 14 controlled in processing unit II-B, No. 1 Single Chip Microcomputer (SCM) system module 6 that process is delivered in operation control link I by high speed SPI bus after forming control instruction or controlling parameter, to carry out artificial interference control to compensation work process；No. 1 Single Chip Microcomputer (SCM) system module 6 in operation control link I then passes through high speed SPI bus by each phase voltage virtual value stored, current effective value, active power, reactive power, power factor, current unbalance factorThe parameters such as each phase compensation capacity pass to communication and No. 2 Single Chip Microcomputer (SCM) system modules 14 in man-machine interaction link II, then displayed by LCD MODULE 11 after magnetic coupler module 13 is isolated, after isolating then through three magnetic coupler modules 15,16,17 afterwards, reach host computer respectively through ethernet communication interface module 18, RS232 interface module 19, RS485 interface module 20；Keysheet module 10 in man-machine interaction link II provides the user parameter and arranges and function selecting interface, finishing man-machine interaction function common with LCD MODULE 11.

Control device of the present invention is adopted to carry out independent reactive-load compensation online or idle as follows with the work process of threephase load imbalance comprehensive compensation simultaneously:

(1) system electrification, self-inspection, initialization；

(2) require to control accordingly setting and the amendment of parameter according to actual motion；

(3) check whether apparatus of the present invention its own system has fault, has during fault and proceeds to corresponding processing program, provide Troubleshooting Tip information, walks downwards execution during fault-free；

(4) power distribution station system three-phase current, instantaneous voltage are constantly gathered；

(5) P, P of calculating in real time and storage power distribution station system_A、P_B、P_C、Q、Q_A、Q_B、Q_C、And current unbalance factor

(6) degree of unbalancednessCompare with 0.2 (or being set in advance in other threshold values in internal memory), whenAutomatically conventional the control of reactive power compensating strategy (such as power factor method, reactive current or reactive power method, nine-area method) is chosen during less than 0.2, whenComprehensive compensation control strategy, the P that will calculate and store then is chosen during be more than or equal to 0.2_A、P_B、P_C、Q_A、Q_B、Q_CSubstitute into the formula (3) in foregoing summary joint, (4), try to achieve (then press without when solvingProcess less than 0.2 situation)；

(7) according to the control strategy output switching instruction chosen, multiple control switch FK is controlled_mnConjunction/transfer is made to change the compound mode compensating Capacitor banks, it is achieved corresponding single reactive-load compensation or idle with threephase load imbalance comprehensive compensation simultaneously；

(8) P, P of power distribution station system are shown in real time_A、P_B、P_C、Q、Q_A、Q_B、Q_C、Deng, and pass to host computer and remotely monitor；

(9) (3) step is repeated.

The ultimate principle of the present invention is described by described above and embodiment, principal character and advantage, particularly show that the marrow place of the inventive method and device obtains system by monitoring power distribution station system three-phase and point phase electric parameter in real time and now carves active power, reactive power, power factor and current unbalance factor, judge whether system exists three-phase load unbalance or the relatively low phenomenon of power factor on this basis, corresponding backoff algorithm is utilized to control Capacitor banks conversion combinative structure afterwards thus realizing the Flexible Control (single reactive-load compensation or idle with threephase load imbalance comprehensive compensation simultaneously) of power distribution station reactive-load compensation.The practical application mode of the present invention is also not restricted to the described embodiments; under the premise without departing from present subject matter scope; the present invention also has various respective change and improvement; these changes and improvements all should fall in the scope of protection of present invention, and protection domain can be defined by the present patent application text appending claims and equivalent thereof.

Claims (5)

1. a power distribution station reactive-load compensation flexible control device, it is characterised in that: it is made up of operation control link (I) and communication and man-machine interaction link (II), between the two by high speed SPI bus exchanging data, wherein:

1.1 operation control links (I) include power distribution station system electric parameter detection and conditioning unit (I-A), key control unit (I-B) and output performance element (I-C) three master sheet units；

Power distribution station system electric parameter and conditioning unit (I-A) are by detecting voltage by three phase module (1), three-phase current detection module (2), switch closes a point state detection module (3), analog signal conditioner circuit module (4), on-off model conditioning circuit module (5) forms, the outfan of detecting voltage by three phase module (1) and three-phase current detection module (2) accesses the input of key control unit (I-B) interior No. 1 Single Chip Microcomputer (SCM) system module (6) after analog signal conditioner circuit module (4) is nursed one's health, switch closes the outfan of point state detection module (3) and processes through on-off model conditioning circuit module (5) and be followed by key control unit (I-B) input of CPLD logical AND combined system module (7) with isolation；

Key control unit (I-B) is made up of No. 1 Single Chip Microcomputer (SCM) system module (6) and CPLD logical AND combined system module (7), and No. 1 Single Chip Microcomputer (SCM) system module (6) is connected with CPLD logical AND combined system module (7) by universal parallel I/O port；

Output performance element (I-C) is outputed return circuit module (9) by power photoelectric coupler module (8) and reactive-load compensation and is formed, and the outfan of key control unit (I-B) interior CPLD logical AND combined system module (7) outputs the input of return circuit module (9) by passing to reactive-load compensation after power photoelectric coupler module (8) isolation；

1.2 communications and man-machine interaction link II include man-machine interaction unit (II-A), computing and control processing unit (II-B) and three master sheet units of communication unit (II-C)；

Man-machine interaction unit (II-A) is made up of Keysheet module (10), LCD MODULE (11), and two modules are connected with No. 2 Single Chip Microcomputer (SCM) system modules (14) in operation processing unit (II-B) by universal parallel I/O port respectively after magnetic coupler module (12,13) is isolated；

Computing is made up of No. 2 Single Chip Microcomputer (SCM) system modules (14) with controlling processing unit (II-B), is connected with No. 1 Single Chip Microcomputer (SCM) system module (6) by high speed SPI bus；

Communication unit (II-C) is made up of ethernet communication interface module (18), RS232 interface module (19), RS485 interface module (20), and sequentially embedded with No. 2 Single Chip Microcomputer (SCM) system modules (14) in control processing unit (II-B) with computing after magnetic coupler module (15,16,17) is isolated respectively UART1, UART2 serial port of their outfan is connected.

2. reactive-load compensation flexible control device in power distribution station according to claim 1, it is characterized in that: the detecting voltage by three phase module (1) in the detection of power distribution station system electric parameter and conditioning unit (I-A) adopts three voltage transformers arranged side by side, and three-phase current detection module (2) adopts three current transformers arranged side by side.

3. reactive-load compensation flexible control device in power distribution station according to claim 1, it is characterised in that: the switch in the detection of power distribution station system electric parameter and conditioning unit closes the input of point state detection module (3) directly from compensating each air switch QF in loop in the reactive compensation system of power distribution station_mAuxiliary contact, m=1,2,3,4, the built-in stabilization modulate circuit being made up of clamp diode, amplitude limit stabilivolt, general capacitance resistance ware in stabilization place reason on-off model conditioning circuit module (5) of switch auxiliary contact is realized；Reactive-load compensation in output performance element (I-C) is outputed return circuit module (9) and is adopted 12 control relays arranged side by side.

4. one kind adopts the power distribution station reactive-load compensation flexible control method controlling device described in claim 1, it is characterised in that:

4.1, the three-phase instantaneous voltage value u of power distribution station system is gathered respectively by the detecting voltage by three phase module (1) of power distribution station reactive-load compensation flexible control device and three-phase current detection module (2)_A(t)、u_B(t)、u_CThe three-phase instantaneous current value i of (t) and distribution transformer wire inlet loop_A(t)、i_B(t)、i_CT (), calculates defined formula according to Instantaneous Power Theory and three-phase alternating current active power, reactive power, power factor and calculates acquisition power distribution station system three phases active power virtual value P, each phase active power virtual value P_A、P_B、P_C, three phase reactive power virtual value Q, each phase reactive power virtual value Q_A、Q_B、Q_C, three-phase activity coefficientAnd each phase power factorAnd be stored in No. 1 Single Chip Microcomputer (SCM) system module (6) in power distribution station reactive-load compensation flexible control device；According to the following equation (1) the three-phase current instantaneous value i to collecting_A(t)、i_B(t)、i_CT () makes symmetrical component transformation, obtain the zero sequence i of current time three-phase current₀, positive sequence i₁, negative sequence component i₂,

$\left[\begin{array}{c}{i}_0\\ i_1\\ i_2\end{array}\right]=\frac{1}{3}\left[\begin{array}{ccc}1& 1& 1\\ 1& \mathrm{\&alpha;}& {\mathrm{\&alpha;}}^2\\ 1& {\mathrm{\&alpha;}}^2& \mathrm{\&alpha;}\end{array}\right]\left[\begin{array}{c}{i}_A\left(t\right)\\ i_B\left(t\right)\\ i_A\left(t\right)\end{array}\right]---\left(1\right),$

Operator α=e in formula^j120°, calculate by following equation (2) afterwards and obtain the instantaneous negative phase-sequence degree of unbalancedness of electric current

${\mathrm{\&epsiv;}}_{I_2}=\frac{i_2}{i_1}---\left(2\right);$

4.2, to calculate acquisitionIt is worth the foundation selecting different Compensation Strategies as power distribution station reactive-load compensation flexible control device, whenAutomatically the control of reactive power compensating strategy well known in the art is chosen during less than device default setting value 0.2, whenComprehensive compensation control strategy is then chosen, each meritorious mutually and reactive power P that namely will obtain by power distribution station reactive-load compensation flexible control device and store during be more than or equal to 0.2_A、P_B、P_C、Q_A、Q_B、Q_CSubstitute into following equation (3), ask for intermediate variable Q_xmin, Q in formula_x1、Q_x2、Q_x3、Q_x4、Q_x5、Q_x6It is intermediate variable, Q_xminMinima for these intermediate variables；

$\left\{\begin{array}{c}{Q}_{x1}<-\frac{4\sqrt{3}}{3}(P_C-P_B)-(-3Q_A+Q_B+Q_C)\\ Q_{x2}<-\frac{4\sqrt{3}}{3}(P_A-P_C)-(Q_A-3Q_B+Q_C)\\ Q_{x3}<-\frac{4\sqrt{3}}{3}(P_B-P_A)-(Q_A+Q_B-3Q_C)\\ Q_{x4}>\frac{8\sqrt{3}}{3}(P_B-P_A)-(Q_A+Q_B+Q_C)\\ Q_{x5}>\frac{8\sqrt{3}}{3}(P_C-P_B)-(Q_A+Q_B+Q_C)\\ Q_{x6}>\frac{8\sqrt{3}}{3}(P_A-P_C)-(Q_A+Q_B+Q_C)\\ Q_x=Q_{x\min }=\min \{Q_{x1},Q_{x2},Q_{x3},Q_{x4},Q_{x5},Q_{x6}\}\end{array}\right.---\left(3\right)$

If Q_xminThere is solution then to be substituted into formula (4), try to achieve Y wiring further respectively and compensate tank capacitors group ideal capacity valueTank capacitance group ideal capacity value is compensated with delta connection

$\left\{\begin{array}{c}{Q}_A^Y=\frac{\sqrt{3}}{3}(P_C-P_B)+\frac{1}{4}(-3Q_A+Q_B+Q_C)+\frac{1}{4}{Q}_{xmin}\\ Q_B^Y=\frac{\sqrt{3}}{3}(P_A-P_C)+\frac{1}{4}(Q_A-3Q_B+Q_C)+\frac{1}{4}{Q}_{xmin}\\ Q_C^Y=\frac{\sqrt{3}}{3}(P_B-P_A)+\frac{1}{4}(Q_A+Q_B-3Q_C)+\frac{1}{4}{Q}_{x\min }\\ Q_{AB}^{\mathrm{\&Delta;}}=\frac{2\sqrt{3}}{3}(P_B-P_A)-\frac{1}{4}(Q_A+Q_B+Q_C)-\frac{1}{4}{Q}_{x\min }\\ Q_{BC}^{\mathrm{\&Delta;}}=\frac{2\sqrt{3}}{3}(P_C-P_B)-\frac{1}{4}(Q_A+Q_B+Q_C)-\frac{1}{4}{Q}_{x\min }\\ Q_{CA}^{\mathrm{\&Delta;}}=\frac{2\sqrt{3}}{3}(P_A-P_C)-\frac{1}{4}(Q_A+Q_B+Q_C)-\frac{1}{4}{Q}_{x\min }\end{array}\right.---\left(4\right),$

If Q_xminThen press without solutionProcess less than 0.2 situation；

4.3, compensating algorithm computing by power distribution station reactive-load compensation flexible control device online according to selected Compensation Strategies, output switching instruction controls each the multiple control switch FK in the system of power distribution station_mnConjunction/transfer is made to change the compound mode structure compensating Capacitor banks to compensate accordingly, m=1,2,3,4, n=1,2,3: when the Compensation Strategies selected is control strategy well known in the art, by multiple control switch FK_mnCapacitor banks is made to be configured to the common benefit of routine and divide a benefit compound mode to be incorporated to system, it is achieved the compensation to System Reactive Power；When the Compensation Strategies selected is comprehensive compensation control strategy, by multiple control switch FK_mnMake Capacitor banks be configured to Y wiring to compensate loop and delta connection and compensate loop combination mode, and bank capability value closest to ideal capacity valueCapacitor banks be incorporated to system, it is achieved to System Reactive Power with threephase load is unbalanced compensates simultaneously.

5. reactive-load compensation flexible control method in power distribution station according to claim 4, it is characterized in that: by No. 1 one-chip computer module (6) in power distribution station reactive-load compensation flexible control device complete electrical quantity read in real time, the realization of reactive-load compensation Flexible Control algorithm and compensate sending of control instruction, by man-machine interaction and communication functions such as the setting of No. 2 one-chip computer module (14) completion system parameters in power distribution station reactive-load compensation flexible control device, display storages.