A kind of low voltage electric load intelligent dispensing system and distribution method
technical field
The present invention relates to a kind of low voltage electric load intelligent dispensing system and distribution method, belong to electric power system distribution power-saving technique field.
background technology
Low voltage electric load, typically refer to exchange 380V system with the overwhelming majority of load ,Zhan China electric load consumption.Exchange 380V system and conventionally by three-phase and four-line, formed, i.e. A phase, B phase, C phase, N phase (zero line), the load of its tape splicing has almost comprised all kinds of modern household electrical appliances and factory's electricity consumption, agricultural irrigation.
For three phase electric machine load, while normally moving, three-phase is in poised state.Concerning residential electricity consumption, its load is nearly all single-phase.Because resident load is normally drawn from transformer with cable, when installer installs, be difficult to know enter the separate of resident, more do not know character and the size of which load.In other words, even know the size of certain load, but due to the seasonality of electricity consumption and period, all can cause the payload of certain phase unpredictable, also be very easy to cause three-phase load uneven.Can say that low-voltage power system three-phase load absolute equilibrium is perfect condition, imbalance is normality.
Three-phase load is uneven, and the harm bringing to electric power system is very serious.First harm is that three-phase load imbalance causes line loss to increase, and the numerical value that line loss increases becomes with electric current square to be directly proportional.In poised state, circuit Sun Hao ⊿ P=I
2r , Qie ⊿ P
a=⊿ P
b=⊿ P
c, the total line loss ∑ of three-phase ⊿ P=3 I
2r; When system is during in non-equilibrium state, suppose that A phase load is zero, B, C two-phase have on average been shared the electric current of A phase, ⊿ P
a=0 , ⊿ P
b=(1.5I)
2r=2.25I
2r , ⊿ P
c=(1.5I)
2r=2.25I
2r , ∑ ⊿ P=4.5 I
2r, line loss has increased by 50%.Be not difficult to calculate, if the load of three-phase by a phase tape splicing, ∑ ⊿ P=(3I now)
2r=9I
2r, when line loss is poised state 3 of line loss times.
Three-phase load is uneven, and the second largest harm bringing to electric power system is that transformer produces additional iron losses.The network distribution transformer three core limb structures that adopt of Y/Yo wiring more, when there is three-phase load imbalance or occurring earth fault, its primary side non-zero-sequence current exists, secondary side has zero-sequence current to exist, therefore the zero-sequence current of secondary side is exciting current completely, the zero sequence magnetic flux producing can not be closed in iron core, need by oil tank wall closure, thereby heating produces iron loss in the annexes such as iron case.
Three-phase load is uneven, and the third-largest harm bringing to electric power system is to produce additional copper loss, and additional copper loss increase can cause transformer heating, reduces the operational efficiency of transformer.
Three-phase load is uneven, and the fourth-largest harm bringing to electric power system is to produce variation.
Therefore, invent a kind of electric load smart allocation method and system is necessary very much, it is by real-time monitoring system three-phase load state, gather the load of each electric load smart allocation terminal (extension set) of native system subordinate, how decision-making next step redistribute load, makes three-phase load remain essentially at any time poised state.
summary of the invention
The object of the invention is, the imbalance problem existing in order to solve low voltage electric load, can realize the size of dynamically adjusting each phase load, make system remain at state in a basic balance, improve transformer operational efficiency, reduce line loss, the present invention proposes and discloses a kind of low voltage electric load intelligent dispensing system and distribution method.
The technical scheme that realizes the object of the invention is, the present invention adopts a kind of for each phase total electricity consumption of real time monitoring distribution transformer, each power load terminal power consumption information of Real-time Collection, and how decision-making redistributes the low voltage electric load smart allocation main frame of load; Also adopt some for gathering each user power utilization amount and uploading to main frame, carry out the electric load smart allocation terminal of main frame transmitting order to lower levels switchable load, i.e. extension set; Then according to electric load smart allocation method, realize the adjusting of terminal electric load and distribution.
Low voltage electric load intelligent dispensing system is comprised of a low voltage electric load smart allocation main frame and some electric load smart allocation terminals (extension set).
Described low voltage electric load smart allocation main frame is comprised of three current transformers (CT), three voltage transformers (PT), CPU, liquid crystal, three-phase communication module; Low voltage electric load smart allocation main frame is for each phase total electricity consumption of real time monitoring distribution transforming, by three-phase communication module, each electric load smart allocation terminal (extension set) power consumption information of Real-time Collection, by CPU, the terminal power information gathering is processed, decision-making goes out how to redistribute load, load unbalanced degree is remained in acceptability limit, and send switching command to electric load smart allocation terminal, will switch to another phase compared with light load compared with the sub-load of heavy load one phase.
Described electric load smart allocation terminal (extension set) is comprised of great current mutual inductor (CT), voltage transformer (PT), power magnetic force keeping relay, large electric current combination switch, threephase switch interlock circuit, communication module, phase identification of circuit, CPU.Described electric load smart allocation terminal uploads to main frame by communication module by each user power utilization information of collection, by phase identification of circuit, load is carried out to phase place evaluation, and carry out main frame transmitting order to lower levels, logical super-high-current combination switch and ghyristor circuit are realized load and are automatically switched, by threephase switch interlock circuit, guarantee all the time under any circumstance, only have a road power supply and user to connect, can not produce short circuit.
System energy real-time tracking load variations, adjusts each phase load size at any time, current unbalance factor is remained in acceptability limit, thereby improve transformer operational efficiency and life-span, reduces line loss.
Described low voltage electric load smart allocation method is:
(1) to distribution transformer, set up a main frame, set up respectively extension set to each power load terminal; Main frame is used for each phase total electricity consumption of real time monitoring distribution transforming, each electric load smart allocation terminal (extension set) power consumption information of Real-time Collection, and decision-making goes out how to redistribute load, and load unbalanced degree is remained in acceptability limit; Described extension set is used for gathering each user power utilization amount and uploads to main frame, execution main frame transmitting order to lower levels, realizes load and automatically switches.
(2) by 3, communicate module, make main frame and extension set keep communicating by letter, the electric current of each extension set of Real-time Collection; By the method by sending mutually data acquisition command, make minute function accurately locate each phase phase sequence, and be strictly consistent with main frame;
(3) when use capacity surpasses certain definite value, press formula Iun=[⊿ Imax (∣ Ia-Iavg ∣ , ∣ Ib-Iavg ∣ , ∣ Ib-Iavg ∣)/Iavg] * 100% calculating degree of unbalance; When degree of unbalance surpasses certain definite value, think that system occurs uneven, and make strategy of load regulation; Wherein, Iavg is the mean value of 3 phase total currents; The current unbalance factor of Iun for calculating in real time;
(4) this terminal, after start, detects the state of each switch immediately, and making only has a switch to close in power magnetic force keeping relay JA, JB, JC, and relay J Z will be in closed position simultaneously.
(5) log-on data capture program, constantly detects size and the character of this terminal institute on-load, and is stored in terminal CPU by certain stipulations, and main frame reads by the time.
(6) when main frame is sent " wanting data " or " Switching power " order by the communication module of certain phase circuit, this orders by a certain phase UA, U0 line, communication module, SIGIN pin, incoming terminal CPU; Terminal CPU(U12) carry out immediately Host Command: if " wanting data ", by the data format of agreement, issues main frame by SIGOUT pin, communication module, UA, U0 data; If want " Switching power ", undertaken by following program: the controllable silicon that closes-disconnection JZ-disconnection controllable silicon--disconnect the switch-controllable silicon that closes that the current switch having closed-the main frame requirement of closing is closed-close JZ-disconnection controllable silicon.
Each step of said process is all confirmed, just carries out next step.Then by switching result, report main frame.
The invention has the beneficial effects as follows, the present invention is by installing respectively low voltage electric load smart allocation main frame and extension set at distribution transformer and sharing of load terminal, adopt low voltage electric load smart allocation method, can be according to the unbalance condition of electric load, to the part uncompensated load phase place that automatically switches in real time, guaranteed that distribution transformer low voltage electric load moves within the scope of the degree of unbalance of regulation.The invention solves due to the uneven problem that causes power wastage of low voltage electric load, operational efficiency and the useful life of greatly having improved transformer.The low voltage electric load smart allocation main frame of low voltage electric load intelligent dispensing system of the present invention and low voltage electric load smart allocation extension set all adopt cmos element, and Overall Power Consumption is extremely low, and normal operation only needs 1W, and use cost is extremely low.
The present invention is applicable to electric power system distribution transformer electric load smart allocation.
accompanying drawing explanation
Fig. 1 is electric load intelligent dispensing system topological diagram;
Wherein, the 1st, distribution transformer; The 11st, distribution transformer high-pressure side; The 12nd, be distribution transformer low-pressure side (380V/220V); The 2nd, low voltage electric load smart allocation main frame; The 31st, low voltage electric load distributing terminals (extension set 1); The 32nd, low voltage electric load distributing terminals (extension set 2); 3N is low voltage electric load distributing terminals (extension set N); The 41st, user 1; The 42nd, user 2; 4N is user N;
Fig. 2 is the conversion of low voltage electric load smart allocation main frame front end and commutation circuit figure;
Fig. 3 is low voltage electric load smart allocation host CPU circuit and RS-485 interface circuit figure;
Fig. 4 is low voltage electric load smart allocation main frame three-phase communication module circuit;
Fig. 5 is low voltage electric load smart allocation terminal threephase switch interlock circuit figure;
Fig. 6 is low voltage electric load smart allocation terminal combination switch silicon controlled control circuit figure;
Fig. 7 is low voltage electric load smart allocation terminal CPU and three-phase communication module circuit diagram.
Embodiment
The embodiment of low voltage electric load smart allocation method of the present invention as shown in Figure 1.
Press shown in Fig. 1, at distribution transformer and sharing of load terminal, low voltage electric load smart allocation main frame and extension set are installed respectively.
(1) by main frame 3, communicate module, make main frame and extension set keep communicating by letter, the electric current of each extension set of Real-time Collection; On main frame, the size of each phase current of this distribution transforming of Real-time Collection (total current), voltage, and be calculated as follows out the Zong Rong Liang ⊿ S of current use:
⊿S=Ia×Ua+Ib×Ub+Ic×Uc
Wherein, Ia, Ib, Ic are each phase total current of distribution transformer output, and Ua, Ub, Uc are each terminal voltage of exporting mutually of distribution transformer;
(2) the capacity S of the Zong Rong Liang ⊿ S>=transformer of current use
0in the time of * 20%, be calculated as follows degree of unbalance Iun:
Iun=[⊿Imax?(∣Ia-Iavg∣,∣Ib-Iavg∣,∣Ic-Iavg∣)/?Iavg]×100%。
Wherein, S
0capacity for transformer; Iavg is the mean value of 3 phase total currents, Iavg=(Ia+Ib+Ic)/3; Iun is the current unbalance factor of calculating in real time, gets in 3 phase currents with the peaked absolute value of 3 phase current mean value differences divided by current average;
(3) establish when current unbalance factor Iun≤15%, think that system is in non-equilibrium state, reply load is adjusted;
(4) main frame, by sending mutually data acquisition command, gathers the current load data of each extension set (ia, ib, ic) storage, one by one until all extension set data acquisitions of native system are complete;
(5) if main frame is pressed public formula ∣ Ia-Iavg ∣, ∣ Ib-Iavg ∣, it is maximum that ∣ Ic-Iavg ∣ calculates out ∣ Ia-Iavg ∣ electric current difference, and ∣ Ic-Iavg ∣ is minimum, and this just means should reduce A phase load, increases C phase load and just can make system power balance.The extension set that the first trial cut First of main frame moves mutually at A is to C phase, obtain new Ia ˊ=Ia-ia after switchable load, new Ic ˊ=Ic+ ia, new mean value Iavg ˊ=(Ia ˊ+Ib+ Ic ˊ)/3, new degree of unbalance Iun ˊ=[⊿ Imax ˊ (∣ Ia ˊ-Iavg ˊ ∣ ∣ Ib-Iavg ∣ , ∣ Ic ˊ-Iavg ˊ ∣)/Iavg ˊ] * 100%;
(6) when Iun ˊ≤15%, main frame from A in opposite directions First extension set send the order of " A is switched to C phase mutually ";
(7) when Iun ˊ >=15%, take out second extension set electric current moving mutually at A, by (5) one step process, calculate Iun ˊ.
If Iun ˊ≤15%, main frame from A in opposite directions second extension set send the order of " A is switched to C phase mutually ".
If Iun ˊ >=15%, takes out the 3rd the extension set electric current moving mutually at A, by (5) one step process, calculate Iun ˊ, and by that analogy, until reach Iun ˊ≤15% after switchable load.
(8) if after above-mentioned calculating, can not find " switching after certain phase load Iun ˊ≤15% " this result, the extension set quantity that proof system is installed very little, is not carried out load switching, simultaneously at certain special symbol of liquid crystal screen display, to show prompting.
Produce unbalanced reason possibility Hai You ∣ Ia-Iavg ∣ great , ∣ Ib-Iavg ∣ little; The little , Huo of ∣ Ib-Iavg ∣ great , ∣ Ia-Iavg ∣ ∣ Ib-Iavg ∣ great , ∣ Ic-Iavg ∣ is little; Several situations such as the little , Huo of ∣ Ic-Iavg ∣ great , ∣ Ia-Iavg ∣ ∣ Ic-Iavg ∣ great , ∣ Ib-Iavg ∣ is little, its processing method principle same as above.
The embodiment of low voltage electric load intelligent dispensing system of the present invention is as shown in Fig. 2 ~ Fig. 7.
Fig. 2 is the conversion of low voltage electric load smart allocation main frame front end and commutation circuit figure, and Fig. 3 is low voltage electric load smart allocation host CPU circuit and RS-485 interface circuit figure, and Fig. 4 is low voltage electric load smart allocation main frame three-phase communication module circuit; Fig. 5 low voltage electric load smart allocation terminal threephase switch interlock circuit figure, Fig. 6 is low voltage electric load smart allocation terminal combination switch silicon controlled control circuit figure, Fig. 7 is low voltage electric load smart allocation terminal CPU and three-phase communication module circuit diagram.
Embodiment of the present invention low voltage electric load intelligent dispensing system is comprised of low voltage electric load smart allocation main frame and low voltage electric load smart allocation terminal.Low voltage electric load smart allocation main frame connects distribution transformer low-pressure end, and low voltage electric load smart allocation terminal connects loaded termination.
Embodiment of the present invention low voltage electric load smart allocation main frame, is comprised of three current transformers (CT1-CT3), three voltage transformers (PT1-PT3), CPU (U6), Liquid Crystal Module (U4), three-phase communication module; Its circuit as shown in Figure 2, Figure 3 and Figure 4.
Current transformer (CT1-CT3) becomes the element of small-signal by large (distribution transforming output total current) current conversion, and its output current signal meets CPU(U6); Voltage transformer (PT1-PT3) converts high voltage (distribution transforming output end voltage) to the element of small-signal, and its winding connects distribution transformer low-pressure end, and the voltage signal of secondary winding output meets CPU.
Liquid crystal (U4) shows the element of various information, meets CPU.
CPU (U6) gather and carry out various calculating, storage, communicate by letter with extension set, the element of issue an order, it accepts each phase small-signal current and voltage of the input of voltage transformer summation current transformer; Accept the signal that three-phase communication module is sent; Send instruction and send signal to terminal extension set by communication module.
Three-phase communication module, can be by the module of communicating by letter with each electric load smart allocation terminal (extension set).
U1, U2 and U3 two 4 select 1 variable connector, and U5 is RS-485 interface chip.
From the three-phase total current of distribution transforming output flow through respectively DCTA, DCTB, DCTC, at secondary, produce the electric current of 0-5A, the CT1 CT2 CT3 that this electric current enters main frame through CZ1, CZ2, CZ3 carries out quadratic transformation, becomes respectively the voltage that certain applicable CPU (U6) gathers on R4, R5, R6.
From the three-phase voltage of distribution transforming output through CZ4, CZ5, CZ6, CZ7, enter main frame through resistance R 1, R2, R3 current limliting are laggard, the PT1 of main frame, PT2, PT3 are transformed into the voltage that certain applicable CPU (U6) gathers.
At CPU(U6) control under, PXX1, PXX2 pin produce the combination of 3 kinds " 0 " and " 1 ", timesharing is connected the output signal of CT1, CT2, CT3 to variable connector U1, and is incorporated into CPU(U6 from 13,3 pin of variable connector U1) I1P, I1N.Meanwhile, timesharing is connected the output signal of PT1, PT2, PT3 to variable connector U2, and is incorporated into CPU(U6 from 13,3 pin of variable connector U2) UP, UN.
CPU(U6) by timesharing, connect 3 phase voltages, electric current to UP, UN, I1P, I1N, calculate in real time size and the degree of unbalance of this distribution transforming output total current, and show on liquid crystal display screen U4 by above-mentioned principle.
When the degree of unbalance of three-phase current surpasses acceptability limit, CPU(U6) start immediately the program that gathers electric current in each electric load smart allocation terminal (extension set) of subordinate.CPU(U6) by certain communication protocol packing, need the data that send, juxtaposition output pin PXX3, PXX4 are certain value.As sent mutually data to A, CPU(U6) by putting output pin PXX3, PXX4 for certain value, SIGA and SIGOUT are connected, that is: 12,13 of variable connector U3 is connected, the data of transmission are through CPU(U6) SIGA-A phase voltage line of 12-13 pin-three-phase communication module of 19 pin-U3.The electric load smart allocation terminal (extension set) of all A of being connected on phases can receive order, but only has the terminal (extension set) that address conforms to the current command just to understand return data.
Embodiment of the present invention low voltage electric load intelligent dispensing system terminal (extension set), great current mutual inductor (CT), voltage transformer (PT), power magnetic force keeping relay, large electric current combination switch, threephase switch interlock circuit, communication module, phase identification of circuit, CPU, consist of, its circuit is as shown in Fig. 5, Fig. 6 and Fig. 7.
The present embodiment low voltage electric load intelligent dispensing system terminal adopts power magnetic force keeping relay, is for the on-load switch of system power supply access user, and it has through-flow large, quiescent dissipation is zero feature;
Large electric current combination switch, composite module in parallel with power magnetic force keeping relay by high-power silicon controlled rectifier, that automatically switch for the commutation of loading, can improve the power magnetic force keeping relay life-span.Low voltage electric load intelligent dispensing system terminal of the present invention adopts large electric current combination switch, has improved the electric break-make life-span of native system low voltage electric load smart allocation terminal.
The threephase switch interlock circuit of the present embodiment low voltage electric load intelligent dispensing system terminal, is for guaranteeing at any time (while comprising that driving element lost efficacy) Jin You mono-road system voltage access user of terminal of the present invention, prevents the circuit of phase fault.
The communication module of the present embodiment low voltage electric load intelligent dispensing system terminal is the module for terminal of the present invention and main-machine communication; Described CPU(U12), be terminal of the present invention for carrying out various calculating, storage, with main-machine communication, carry out the element of Host Command.
The phase identification of circuit of the present embodiment low voltage electric load intelligent dispensing system terminal is for determining that terminal A of the present invention, B, C three-phase voltage inlet wire keep and A, the B of main frame, the circuit that C three-phase voltage is corresponding.
The present embodiment low voltage electric load intelligent dispensing system terminal, after start, detects the state of each switch immediately, and making only has a switch to close in JA, JB, JC, and JZ will be in closed position simultaneously.
During the present embodiment low voltage electric load smart allocation terminal works, first log-on data capture program, constantly detects size and the character of this terminal institute on-load, and is stored in CPU (U12) by certain stipulations, and main frame reads by the time.
When low voltage electric load smart allocation main frame is sent " wanting data " or " Switching power " order by the communication module of certain phase circuit, this order, by UA, U0 line, communication module, SIGIN pin, arrives U12(CPU).This terminal CPU(U12) carry out immediately Host Command.If " want data ",, by the data format of agreement, by SIGOUT pin, communication module, UA, U0, data are issued to main frame.If want " Switching power ", undertaken by following program: close controllable silicon-disconnection JZ-disconnection controllable silicon--disconnect the switch that the current switch having closed-the main frame requirement of closing is closed-close controllable silicon-close JZ-disconnection controllable silicon.Each step of said process is all confirmed, just carries out next step.Then switching result report main frame.