CN205231758U - Power supply system with current balance regulatory function - Google Patents

Abstract

The utility model discloses a power supply system, this power supply system includes: transformer substation and unbalanced three phase load, it will to be used for the unbalanced three phase load with the transmission line that the transformer substation connects, transmission line includes: first phase line, second phase line, third phase line and the neutral conductor, with the electric current balance adjustment device that transmission line connects, electric current balance adjustment device is three -phase half -bridge frequency control ware, wherein, electric current balance adjustment device is used for adjusting among the transmission line first phase line the second phase line and the third phase line is close to the electric current of transformer substation's one end is in balanced state. Power supply system has set up and has been used for adjusting among the transmission line first phase line the second phase line and the third phase line is close to the electric current of transformer substation's one end is in balanced state's electric current balance adjustment device, can solve the unbalanced three phase problem so that the triple line intermediate -current is balanced.

Description

A kind of electric power system with current balance type regulatory function

Technical field

The utility model relates to electric power system technical field, more particularly, relates to a kind of electric power system with current balance type regulatory function.

Background technology

Three-phase imbalance refers to that three-phase current (or voltage) amplitude is inconsistent in electric power system, and difference in magnitude exceedes prescribed limit.The asynchronism of each phase load skewness, single-phase load electricity consumption and single-phase high-power load access are the main causes causing three-phase imbalance, owing to there is a large amount of single-phase loads in city domestic power grid and agricultural power network, cause three-phase imbalance phenomenon ubiquity in modern power network and particularly serious.

Three-phase imbalance in electrical network can increase circuit and transformer copper loss, increase transformer iron loss, reduce transformer to exert oneself and even can affect the safe operation of transformer, can imbalance of three-phase voltage be caused thus reduce power supply quality, even can affect electric energy and become the precision sent and then cause metering loss.

Therefore, the three-phase imbalance problem in electrical network that how to solve is a problem urgently to be resolved hurrily in electric power system field.

Utility model content

For solving the problems of the technologies described above, the utility model provides a kind of electric power system with current balance type regulatory function, and this electric power system can make current balance type in triple line, solves three-phase imbalance problem.

For achieving the above object, the utility model provides following technical scheme:

Have an electric power system for current balance type regulatory function, this electric power system comprises:

Transformer station and three-phase imbalance load;

For the transmission line be connected with described transformer station by described three-phase imbalance load, described transmission line comprises: the first phase line, the second phase line, third phase line and the neutral line;

The current balance type adjusting device be connected with described transmission line; Described current balance type adjusting device is three-phase half-bridge power regulators;

Wherein, described current balance type adjusting device is in poised state for regulating the first phase line described in described transmission line, described second phase line and the electric current of described third phase line near described transformer station one end.

Preferably, in above-mentioned electric power system, described three-phase half-bridge power regulators comprises: energy storage device, first-phase branch road, second-phase branch road and third phase branch road;

Described energy storage device is all connected with described first-phase branch road, described second-phase branch road and described third phase branch road; Described first-phase branch road is connected with described first phase line; Described second-phase branch road is connected with described second phase line; Described third phase branch road is connected with described third phase line;

Described energy storage device for storing in described first phase line, described second phase line and described third phase line electric current higher than the electric energy of balanced balanced current circuit, for carrying out current compensation for electric current in three lower than the circuit of balanced balanced current.

Preferably, in above-mentioned electric power system, described energy storage device comprises: the first storage capacitor and the second storage capacitor;

Wherein, the bottom crown of described first storage capacitor is connected with the top crown of described second storage capacitor, and is connected with the described neutral line; The top crown of described first storage capacitor connects first node, and the bottom crown of described second storage capacitor connects Section Point.

Preferably, in above-mentioned electric power system, described first-phase branch road comprises: the first coil, the first transistor, transistor seconds, the first diode and the second diode;

First pole of the first transistor is extremely all connected with described first phase line by described first coil with second of transistor seconds;

Second pole of the first transistor connects described first node, control end input control signal;

First pole of transistor seconds connects described Section Point, control end input control signal;

The positive pole of described first diode connects the first pole of described the first transistor, and negative pole connects the second pole of described the first transistor;

The positive pole of described second diode connects the first pole of described transistor seconds, and negative pole connects the second pole of described transistor seconds.

Preferably, in above-mentioned electric power system, described second-phase branch road comprises: the second coil, third transistor, the 4th transistor, the 3rd diode and the 4th diode;

First pole of third transistor and second of the 4th transistor is extremely all connected with described second phase line by described second coil;

Second pole of third transistor connects described first node, control end input control signal;

First pole of the 4th transistor connects described Section Point, control end input control signal;

The positive pole of described 3rd diode connects the first pole of described third transistor, and negative pole connects the second pole of described third transistor;

The positive pole of described 4th diode connects the first pole of described 4th transistor, and negative pole connects the second pole of described 4th transistor.

Preferably, in above-mentioned electric power system, described third phase branch road comprises: tertiary coil, the 5th transistor, the 6th transistor, the 5th diode and the 6th diode;

First pole of the 5th transistor and second of the 6th transistor is extremely all connected with described third phase line by described tertiary coil;

Second pole of the 5th transistor connects described first node, control end input control signal;

First pole of the 6th transistor connects described Section Point, control end input control signal;

The positive pole of described 5th diode connects the first pole of described 5th transistor, and negative pole connects the second pole of described 5th transistor;

The positive pole of described 6th diode connects the first pole of described 6th transistor, and negative pole connects the second pole of described 6th transistor.

As can be seen from technique scheme, electric power system provided by the utility model comprises: transformer station and three-phase imbalance load; For the transmission line be connected with described transformer station by described three-phase imbalance load, described transmission line comprises: the first phase line, the second phase line, third phase line and the neutral line; The current balance type adjusting device be connected with described transmission line; Described current balance type adjusting device is three-phase half-bridge power regulators; Wherein, described current balance type adjusting device is in poised state for regulating the first phase line described in described transmission line, described second phase line and the electric current of described third phase line near described transformer station one end.Described electric power system is provided with the current balance type adjusting device for regulating the first phase line described in described transmission line, described second phase line and the electric current of described third phase line near described transformer station one end to be in poised state, current balance type in triple line can be made, solve three-phase imbalance problem.

Accompanying drawing explanation

In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only embodiment of the present utility model, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to the accompanying drawing provided.

The structural representation of a kind of electric power system that Fig. 1 provides for the embodiment of the present application;

The structural representation of a kind of power governor of voltage-source type back-to-back that Fig. 2 provides for the embodiment of the present application;

The structural representation of a kind of three-phase half-bridge power regulators that Fig. 3 provides for the embodiment of the present application;

The structural representation of a kind of four phase current transformer power governors that Fig. 4 provides for the embodiment of the present application.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only the utility model part embodiment, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.

The normal table that three-phase imbalance problem can affect electric power system runs, and affects performance and the useful life of power supply unit.The method of current improvement electrical network three-phase imbalance has uniformly distributed, increases the methods such as capacity of short circuit, inductance and capacitor combination adjustment, although these administering method can obtain certain benefit, but limit by conditions such as floor space, objectivity, economy, be difficult to implement, can not tackle the problem at its root.

In order to solve the problem, the embodiment of the present application provides circuit a kind of electric power system with current balance type regulatory function, and the structure of described electric power system as shown in Figure 1.

With reference to the structural representation of a kind of electric power system that figure 1, Fig. 1 provides for the embodiment of the present application, this electric power system comprises: transformer station 11 and three-phase imbalance load 12; For the transmission line that described three-phase imbalance load 12 is connected with described transformer station 11; The current balance type adjusting device 13 be connected with described transmission line.

Wherein, described transmission line comprises: the first phase line A, the second phase line B, third phase line C and neutral line N.Described current balance type adjusting device 13 is in poised state for regulating the first phase line A described in described transmission line, described second phase line B and the electric current of described third phase line C near described transformer station 11 one end.

Optionally, described current balance type adjusting device 13 is voltage-source type power governor back-to-back.The structure of the described power governor of voltage-source type back-to-back as shown in Figure 2.

With reference to figure 2, the structural representation of a kind of power governor of voltage-source type back-to-back that Fig. 2 provides for the embodiment of the present application, the described power governor of voltage-source type back-to-back comprises: for carrying out the first branch road 21 of Current adjustment between described first phase line A and described second phase line B; For carrying out the second branch road 22 of Current adjustment between described second phase line B and described third phase line C; For carrying out the 3rd branch road 23 of Current adjustment between described first phase line A and described third phase line C.

The circuit structure of described first branch road 21, described second branch road 22 and described 3rd branch road 23 is identical.

Described first branch road 21 comprises: the first transformer substation side transformer T11, the first control capacittance C1, the first load-side transformer T12.Described neutral line N and described first phase line A is connected with described first control capacittance C1 by described first transformer substation side transformer T11 near one end of described transformer station 11; Between described first transformer substation side transformer T11 and described first control capacittance C1, there is switching device K.

Described neutral line N and described second phase line B is connected with described first control capacittance by described first load-side transformer T12 near one end of described three-phase imbalance load 13; Between described first load-side transformer T12 and described first control capacittance C1, there is switching device K.

Described first control capacittance C1 is used for the electric energy of storaging current higher than the phase line of balanced balanced current, and compensates electric energy for the phase line being less than described balanced balanced current for electric current.The conducting state of the first phase line A and the first control capacittance C1 can be controlled by the switching device K on the left of the first control capacittance C1, controlled the conducting state of the second phase line B and the first control capacittance C1 by the switching device K on the right side of control capacittance C1.

First phase line A, higher than balanced balanced current is then charged by the first phase line A and the first control capacittance C near one end electric current of transformer station.Second phase line B, higher than balanced balanced current is then charged by the second phase line B and the first control capacittance C near one end electric current of transformer station.When the first phase line A near one end electric current of transformer station lower than balanced balanced current time, the first control capacittance C1 discharges to the first phase line A, carries out current compensation to the first phase line A, makes its electric current be in balanced balanced current.When the second phase line B near one end electric current of transformer station lower than balanced balanced current time, the first control capacittance C1 discharges to the second phase line B, carries out current compensation to the second phase line B, makes its electric current be in balanced balanced current.

Described second branch road 22 comprises: the second transformer substation side transformer T21, the second control capacittance C2, the second load-side transformer T22;

Described neutral line N and described second phase line B is connected with described second control capacittance C2 by described second transformer substation side transformer T21 near one end of described transformer station 11; Between described second transformer substation side transformer T21 and described second control capacittance C2, there is switching device K.

Described neutral line N and described third phase line C is connected by described second load-side transformer T22 near one end of described three-phase imbalance load 12; Between described second load-side transformer T22 and described second control capacittance C2, there is switching device K;

Described second control capacittance C2 is used for the electric energy of storaging current higher than the phase line of balanced balanced current, and compensates electric energy for the phase line being less than described balanced balanced current for electric current.

Described second branch road 22 is identical with the Current adjustment principle of described first branch road 21 to described second phase line B and described first phase line A with the Current adjustment principle of described third phase line C to described second phase line B, does not repeat them here.

Described 3rd branch road 23 comprises: the 3rd transformer substation side transformer T31, the 3rd control capacittance C3, the 3rd load-side transformer T32.

Described neutral line N and described first phase line A is connected with described 3rd control capacittance C3 by described 3rd transformer substation side transformer T31 near one end of described transformer station 11; Between described 3rd transformer substation side transformer T31 and described 3rd control capacittance C3, there is switching device K.

Described neutral line N and described third phase line C is connected by described 3rd load-side transformer T32 near one end of described three-phase imbalance load 13; Between described 3rd load-side transformer T32 and described 3rd control capacittance C3, there is switching device K.

Described 3rd control capacittance C3 is used for the electric energy of storaging current higher than the phase line of balanced balanced current, and compensates electric energy for the phase line being less than described balanced balanced current for electric current.

Described 3rd branch road 23 is identical with the Current adjustment principle of described first branch road 21 to described second phase line B and described first phase line A with the Current adjustment principle of described third phase line C to described first phase line A, does not repeat them here.

Optionally, described in each, switching device K comprises: transistor Q and diode D;

Described transistor Q comprises: control end, the first pole and the second pole; Described first pole is connected with the positive pole of described diode D; Described second pole is connected with the negative pole of described diode D; Described control end input control signal.When described control signal controls described transistor turns, corresponding transformer and control capacittance conducting.

For the switching device K between described first transformer substation side transformer T11 and described first control capacittance C1, on the left of first transformer substation side transformer T11, the lower end of coil is directly connected with the bottom crown of the first control capacittance C1, and on the left of the first transformer substation side transformer T11, the upper end of coil is connected with the top crown of the first control capacittance C1 by first pole and second of transistor Q is extremely rear.The control signal inputted by control end controls the conducting state of transistor Q.

In Fig. 2 illustrated embodiment, triple line three groups can be divided between two, by three branch roads of the described power governor of voltage-source type back-to-back, the electric current of two-phase circuit of a group each other balance adjustment can be carried out.

In the embodiment of the present application, described current balancing device 13 can also be three-phase half-bridge power regulators.The structure of described three-phase half-bridge power regulators as shown in Figure 3.

With reference to the structural representation of a kind of three-phase half-bridge power regulators that figure 3, Fig. 3 provides for the embodiment of the present application, described three-phase half-bridge power regulators comprises: energy storage device CS, first-phase branch road 31, second-phase branch road 32 and third phase branch road 33.

Described energy storage device CS is all connected with described first-phase branch road 31, described second-phase branch road 32 and described third phase branch road 33; Described first-phase branch road 31 is connected with described first phase line A; Described second-phase branch road 32 is connected with described second phase line B; Described third phase branch road 33 is connected with described third phase line C.

Described energy storage device CS is for storing in described first phase line A, described second phase line B and described third phase line C electric current higher than the electric energy of balanced balanced current circuit, for carrying out current compensation for electric current in three lower than the circuit of balanced balanced current, and then make the electric current in described first phase line A, described second phase line B and described third phase line C keep balance near one end of transformer station 11, namely electric current is identical.

As shown in Figure 3, described energy storage device CS comprises: the first storage capacitor C31 and the second storage capacitor C32.Wherein, the bottom crown of described first storage capacitor C31 is connected with the top crown of described second storage capacitor C32, and is connected with described neutral line N; The top crown of described first storage capacitor C31 connects first node J31, and the bottom crown of described second storage capacitor C32 connects Section Point J32.

Described first-phase branch road 31 comprises: the first coil L31, the first transistor Q31, transistor seconds Q32, the first diode D31 and the second diode D32.First pole of the first transistor Q31 is extremely all connected with described first phase line A by described first coil L31 with second of transistor seconds Q32.Second pole of the first transistor Q31 connects described first node J31, control end input control signal.First pole of transistor seconds Q32 connects described Section Point J32, control end input control signal.The positive pole of described first diode D31 connects first pole of described the first transistor Q31, and negative pole connects second pole of described the first transistor Q31.The positive pole of described second diode D32 connects first pole of described transistor seconds Q32, and negative pole connects second pole of described transistor seconds Q32.

Described second-phase branch road 32 comprises: the second coil L32, third transistor Q33, the 4th transistor Q34, the 3rd diode D33 and the 4th diode D34.First pole of third transistor Q33 is extremely all connected with described second phase line B by described second coil L32 with second of the 4th transistor Q34.Second pole of third transistor Q33 connects described first node J31, control end input control signal.First pole of the 4th transistor Q34 connects described Section Point J32, control end input control signal; The positive pole of described 3rd diode D33 connects first pole of described third transistor Q33, and negative pole connects second pole of described third transistor Q33.The positive pole of described 4th diode D34 connects first pole of described 4th transistor Q34, and negative pole connects second pole of described 4th transistor Q34.

Described third phase branch road comprises: tertiary coil L33, the 5th transistor Q35, the 6th transistor Q36, the 5th diode D35 and the 6th diode D36.First pole of the 5th transistor Q35 is extremely all connected with described third phase line C by described tertiary coil L33 with second of the 6th transistor Q36.Second pole of the 5th transistor Q35 connects described first node J31, control end input control signal.First pole of the 6th transistor Q36 connects described Section Point J32, control end input control signal.The positive pole of described 5th diode D35 connects first pole of described 5th transistor Q35, and negative pole connects second pole of described 5th transistor Q35.The positive pole of described 6th diode D36 connects first pole of described 6th transistor Q36, and negative pole connects second pole of described 6th transistor Q36.

In the embodiment shown in fig. 3, each phase branch road is a brachium pontis, is undertaken charging or discharging by described energy storage device CS, and each brachium pontis both can to circuit power output, also can absorbed power, but each brachium pontis absorbs, active power of output and be approximately zero.Controlled the on off state of transistor by the control signal of each transistor, and then can to control energy storage device CS be that corresponding phase circuit carries out current compensation or current absorption, and then regulate the current balance type of three-phase line.

In the embodiment of the present application, described current balancing device 13 can also be four phase current transformer power governors.The structure of described four phase current transformer power governors as shown in Figure 4.

With reference to figure 4, the structural representation of a kind of four phase current transformer power governors that Fig. 4 provides for the embodiment of the present application, described four phase current transformer power governors comprise: energy storage device C41, first-phase branch road 41, second-phase branch road 42, third phase branch road 43 and the 4th phase branch road 44.

Described energy storage device C41 is all connected with described first-phase branch road 41, described second-phase branch road 42, described third phase branch road 43 and described 4th phase branch road 44; Described first-phase branch road 41 is connected with described first phase line A; Described second-phase branch road 42 is connected with described second phase line B; Described third phase branch road 43 is connected with described third phase line C; Described 4th phase branch road 44 is connected with described neutral line N.

Described energy storage device C41 is for storing in described first phase line 41, described second phase line 42 and described third phase line 43 electric current higher than the electric energy of balanced balanced current circuit, for carrying out current compensation for electric current in three lower than the circuit of balanced balanced current, and then make the electric current in described first phase line A, described second phase line B and described third phase line C keep balance near one end of transformer station 11, namely electric current is identical.

As shown in Figure 4, described energy storage device C41 comprises: storage capacitor; Wherein, the top crown of described storage capacitor connects first node J41, and the bottom crown of described storage capacitor connects Section Point J42.

Described first-phase branch road 41 comprises: the first coil L41, the first transistor Q41, transistor seconds Q42, the first diode D41 and the second diode D42.First pole of the first transistor Q41 is extremely all connected with described first phase line A by described first coil L41 with second of transistor seconds Q42.Second pole of the first transistor Q41 connects described first node J41, control end input control signal.First pole of transistor seconds Q42 connects described Section Point J42, control end input control signal.The positive pole of described first diode D41 connects first pole of described the first transistor Q41, and negative pole connects second pole of described the first transistor Q41.The positive pole of described second diode D42 connects first pole of described transistor seconds Q42, and negative pole connects second pole of described transistor seconds Q42.

Described second-phase branch road 42 comprises: the second coil L42, third transistor Q43, the 4th transistor Q44, the 3rd diode D43 and the 4th diode D44.First pole of third transistor Q43 is extremely all connected with described second phase line B by described second coil L42 with second of the 4th transistor Q44.Second pole of third transistor Q43 connects described first node J41, control end input control signal.First pole of the 4th transistor Q44 connects described Section Point J42, control end input control signal.The positive pole of described 3rd diode D43 connects first pole of described third transistor Q43, and negative pole connects second pole of described third transistor Q43.The positive pole of described 4th diode D44 connects first pole of described 4th transistor Q44, and negative pole connects second pole of described 4th transistor Q44.

Described third phase branch road 43 comprises: tertiary coil L43, the 5th transistor Q45, the 6th transistor Q46, the 5th diode D45 and the 6th diode D46.First pole of the 5th transistor Q45 is extremely all connected with described third phase line C by described tertiary coil L43 with second of the 6th transistor Q46.Second pole of the 5th transistor Q45 connects described first node J41, control end input control signal.First pole of the 6th transistor Q46 connects described Section Point J42, control end input control signal.The positive pole of described 5th diode D45 connects first pole of described 5th transistor Q45, and negative pole connects second pole of described 5th transistor Q45.The positive pole of described 6th diode D46 connects first pole of described 6th transistor Q46, and negative pole connects second pole of described 6th transistor Q46.

Described 4th phase branch road 44 comprises: the 7th transistor Q47, the 8th transistor Q48, the 7th diode D47 and the 8th diode D48.First pole of the 7th transistor Q47 and second of the 8th transistor Q48 is extremely all connected with described neutral line N.Second pole of the 7th transistor Q47 connects described first node J41, control end input control signal.First pole of the 8th transistor Q48 connects described Section Point J42, control end input control signal.The positive pole of described 7th diode D47 connects first pole of described 7th transistor Q47, and negative pole connects second pole of described 7th transistor Q47.The positive pole of described 8th diode D48 connects first pole of described 8th transistor Q48, and negative pole connects second pole of described 8th transistor Q48.

In an embodiment shown in fig. 4, each circuit for the electric power system of three-phase and four-line both provides a phase branch road, for Current adjustment.For the first phase line A, the second phase line B and third phase line C, the on off state of transistor is controlled by the control signal of each transistor of corresponding phase branch road, and then energy storage device 41 can be controlled carry out current compensation or current absorption for corresponding phase circuit, and then regulate the current balance type of three-phase line.

Especially, in Fig. 4 illustrated embodiment, the 4th phase branch road is connected with neutral line N, for suppressing the zero-sequence current in three-phase four-wire system.This circuit may be used for the larger occasion of bearing power.

Fig. 4 illustrated embodiment can carry out three-phase load unbalance adjustment from user side or branch side, its objective is and ensures that the load of three-phase and four-line circuit is balance.So, the three-phase current amplitude of transformer substation side is also necessarily comparatively close, is namely in poised state.

Optionally, described current balance type adjusting device 13 also comprises: drive circuit and controller.Wherein, described controller is connected with described drive circuit.Described drive circuit is connected with the control end of transistor in each switching device.Described controller by described drive circuit for each switching device provides control signal.Each switching device connects the different port of drive circuit, for obtaining independent control signal.

Described electric power system also comprises collector, and described collector is for gathering secondary side voltage signal (u _a(t), u _b(t), u _c(t)) and total input-wire electric current CT secondary side current signal (i _a(t), i _b(t), i _c(t)) signal, carry out digital sample to three-phase voltage and current signal, every cycle adopts 128 points (sample rate is 6.4kHz), obtains the busbar voltage (u of digital quantity _a(n), u _b(n), u _c(n)) and total input-wire electric current (i _a(n), i _b(n), i _c(n)).

Controller also for carrying out discrete Fourier transform (DFT) to the digital quantity of electric power system busbar voltage and total input-wire electric current, obtains busbar voltage phasor and total input-wire electric current phasor, wherein A phase phase voltage phasor with A phase line current phasor computational methods be:

$\left\{\begin{array}{c}{\stackrel{\·}{U}}_A=\underset{n=0}{\overset{128}{\Σ}}{u}_A\left(n\right)e^{-j\frac{\mathrm{\π}}{64}}=\underset{n=0}{\overset{127}{\Σ}}{u}_A\left(n\right)(\cos \frac{\mathrm{\π}}{64}-j\sin \frac{\mathrm{\π}}{64})\\ {\stackrel{\·}{I}}_A=\underset{n=0}{\overset{128}{\Σ}}{i}_A\left(n\right)e^{-j\frac{\mathrm{\π}}{64}}=\underset{n=0}{\overset{127}{\Σ}}{i}_A\left(n\right)(\cos \frac{\mathrm{\π}}{64}-j\sin \frac{\mathrm{\π}}{64})\end{array}\right.$

By that analogy, controller is also for obtaining B, C voltage phasor with line current phasor with

Controller also for carrying out symmetrical component method decomposition to electric power system busbar voltage phasor and total input-wire electric current phasor, obtains positive sequence component and the negative sequence component of three-phase imbalance electric power system busbar voltage and total input-wire electric current.

The zero sequence of busbar voltage, positive sequence and positive sequence component calculate according to the following formula:

$\left[\begin{array}{c}{\stackrel{\·}{U}}_Z\\ {\stackrel{\·}{U}}_P\\ {\stackrel{\·}{U}}_N\end{array}\right]=\frac{1}{3}\left[\begin{array}{ccc}1& 1& 1\\ 1& a& a^2\\ 1& a^2& a\end{array}\right]\·\left[\begin{array}{c}{\stackrel{\·}{U}}_A\\ {\stackrel{\·}{U}}_B\\ {\stackrel{\·}{U}}_C\end{array}\right]$

In formula: j is imaginary unit; $\mathrm{\α}=e^{j2\mathrm{\π}/3}=-1/2+j\sqrt{3}/2;{\mathrm{\α}}^2=e^{j4\mathrm{\π}/3}=-1/2-j\sqrt{3}/2.$

The zero sequence of three-phase imbalance electric power system total input-wire electric current, positive sequence and negative-sequence current component calculate according to the following formula:

$\left[\begin{array}{c}{\stackrel{\·}{I}}_Z\\ {\stackrel{\·}{I}}_P\\ {\stackrel{\·}{I}}_N\end{array}\right]=\frac{1}{3}\left[\begin{array}{ccc}1& 1& 1\\ 1& a& a^2\\ 1& a^2& a\end{array}\right]\·\left[\begin{array}{c}{\stackrel{\·}{I}}_A\\ {\stackrel{\·}{I}}_B\\ {\stackrel{\·}{I}}_C\end{array}\right]$

In formula: j is imaginary unit; $\mathrm{\α}=e^{j2\mathrm{\π}/3}=-1/2+j\sqrt{3}/2;{\mathrm{\α}}^2=e^{j4\mathrm{\π}/3}=-1/2-j\sqrt{3}/2.$

The computational methods of three-phase power supply system degree of unbalance

Three-phase voltage zero sequence degree of unbalance:

The three-phase voltage negative phase-sequence degree of balance:

Three-phase current zero sequence degree of unbalance:

The three-phase current negative phase-sequence degree of balance:

When electric power system described in the embodiment of the present application is run, gathered the real-time current of a phase circuit by external impressed current instrument transformer (CT), then send to controller to process in the electric current of collection.After controller is analyzed, if find three-phase imbalance problem, controller calculates the current value that three-phase current reaches the required conversion of poised state.After calculating completes, controller will drive each switching device to carry out corresponding actions by drive circuit, carries out current regulation control, from newly distributing electric current, makes three-phase current identical, and the three-phase total current of electric power system remains unchanged.Certainly, this a series of calculating and control action complete all in a short period of time, and, current balance type adjusting device just plays an effect of again shunting in this course, only need consume the energy (as the energy ezpenditure of fan running, control device, the energy ezpenditure of switching device) of a very little part.

Illustrating, is every phase 10A electric current during electric power system transformer substation side triple line poised state, and after there is three-phase imbalance problem, the first phase line A electric current is 5A, and the second phase line B electric current is 10A, and third phase line C electric current is 15A.First phase line A electric current then needs to increase the electric current of 5A as reached poised state, the second phase line B electric current be just in time 10A without the need to adjustment, third phase line C electric current wants to reach the electric current that poised state then needs minimizing 5A.After calculating completes, controller will carry out driving switch device action by drive circuit, thus makes electric current from third phase line C inflow current balance regulator 5A, flows out 5A to the first phase line A from current balance type adjusting device inside.Thus A, B, C three-phase current is all redistributed as 10A, and the three-phase total current of system remains unchanged.

In the embodiment of the present application, described transistor can be IGBT.

Described in the embodiment of the present application, current balance type adjusting device tool has the following advantages: possess no-power compensation function, and cos Φ can reach 0.99 grade; Possess three phase unbalance current compensate function, tri-phase unbalance factor can be down to less than 3%; Real-Time Compensation, total reponse time is less than 15ms; Dynamic response time is less than 50 μ s; Nothing is crossed and is mended, without owing benefit, resonance free.

It should be noted that, the adjusting device of current balance type described in the embodiment of the present application, for regulating the current balance type near one end of transformer station side in each phase circuit, makes the electric current of triple line near one end of transformer station side all identical.

Known by foregoing description, the electric power system that the embodiment of the present application provides is provided with the current balance type adjusting device for regulating the first phase line described in described transmission line, described second phase line and the electric current of described third phase line near described transformer station one end to be in poised state, current balance type in triple line can be made, solve three-phase imbalance problem.

To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the utility model.To be apparent for those skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein when not departing from spirit or scope of the present utility model, can realize in other embodiments.Therefore, the utility model can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.

Claims (6)

1. there is an electric power system for current balance type regulatory function, it is characterized in that, comprising:

Transformer station and three-phase imbalance load;

For the transmission line be connected with described transformer station by described three-phase imbalance load, described transmission line comprises: the first phase line, the second phase line, third phase line and the neutral line;

The current balance type adjusting device be connected with described transmission line; Described current balance type adjusting device is three-phase half-bridge power regulators;

Wherein, described current balance type adjusting device is in poised state for regulating the first phase line described in described transmission line, described second phase line and the electric current of described third phase line near described transformer station one end.

2. electric power system according to claim 1, is characterized in that, described three-phase half-bridge power regulators comprises: energy storage device, first-phase branch road, second-phase branch road and third phase branch road;

Described energy storage device is all connected with described first-phase branch road, described second-phase branch road and described third phase branch road; Described first-phase branch road is connected with described first phase line; Described second-phase branch road is connected with described second phase line; Described third phase branch road is connected with described third phase line;

Described energy storage device for storing in described first phase line, described second phase line and described third phase line electric current higher than the electric energy of balanced balanced current circuit, for carrying out current compensation for electric current in three lower than the circuit of balanced balanced current.

3. electric power system according to claim 2, is characterized in that, described energy storage device comprises: the first storage capacitor and the second storage capacitor;

Wherein, the bottom crown of described first storage capacitor is connected with the top crown of described second storage capacitor, and is connected with the described neutral line; The top crown of described first storage capacitor connects first node, and the bottom crown of described second storage capacitor connects Section Point.

4. electric power system according to claim 3, is characterized in that, described first-phase branch road comprises: the first coil, the first transistor, transistor seconds, the first diode and the second diode;

First pole of the first transistor is extremely all connected with described first phase line by described first coil with second of transistor seconds;

Second pole of the first transistor connects described first node, control end input control signal;

First pole of transistor seconds connects described Section Point, control end input control signal;

The positive pole of described first diode connects the first pole of described the first transistor, and negative pole connects the second pole of described the first transistor;

The positive pole of described second diode connects the first pole of described transistor seconds, and negative pole connects the second pole of described transistor seconds.

5. electric power system according to claim 3, is characterized in that, described second-phase branch road comprises: the second coil, third transistor, the 4th transistor, the 3rd diode and the 4th diode;

First pole of third transistor and second of the 4th transistor is extremely all connected with described second phase line by described second coil;

Second pole of third transistor connects described first node, control end input control signal;

First pole of the 4th transistor connects described Section Point, control end input control signal;

The positive pole of described 3rd diode connects the first pole of described third transistor, and negative pole connects the second pole of described third transistor;

The positive pole of described 4th diode connects the first pole of described 4th transistor, and negative pole connects the second pole of described 4th transistor.

6. electric power system according to claim 3, is characterized in that, described third phase branch road comprises: tertiary coil, the 5th transistor, the 6th transistor, the 5th diode and the 6th diode;

First pole of the 5th transistor and second of the 6th transistor is extremely all connected with described third phase line by described tertiary coil;

Second pole of the 5th transistor connects described first node, control end input control signal;

First pole of the 6th transistor connects described Section Point, control end input control signal;

The positive pole of described 5th diode connects the first pole of described 5th transistor, and negative pole connects the second pole of described 5th transistor;

The positive pole of described 6th diode connects the first pole of described 6th transistor, and negative pole connects the second pole of described 6th transistor.