CN105226686A - A kind of imbalance and reactive power compensation integrated control system and method thereof - Google Patents

Abstract

The invention discloses a kind of imbalance and reactive power compensation integrated control system and method thereof, system comprises general controller and multiple alternate compensation arrangement, concrete grammar is as follows: detect distribution transforming exit potential and electric current, and calculate active power, reactive power, power factor (PF), rate of qualified voltage and tri-phase unbalance factor ε; Judge whether phase voltage runs off voltage upper and lower limit: if phase voltage exceedes upper voltage limit, then issue the compensation arrangement order between excision phase-zero; If phase voltage is lower than lower voltage limit, then issue the compensation arrangement order between input phase-zero; If phase voltage is limit with within the scope of upper voltage limit under voltage, then judge that whether tri-phase unbalance factor ε is qualified; If ε & is gt; ε ₀, then the compensation arrangement action command of phase-alternate is issued according to imbalance compensation algorithm; Otherwise the compensation arrangement action command of compensation arrangement between phase-zero and phase-alternate is issued according to Arithmetic for Reactive Power Compensation.The present invention can improve the power factor of electric power system, rural power grids rate of qualified voltage and power supply reliability.

Description

A kind of imbalance and reactive power compensation integrated control system and method thereof

Technical field

The present invention relates to a kind of imbalance and reactive power compensation integrated control system and method thereof, belong to distribution network technology field.

Background technology

Along with the fast development of rural economy, electrical energy demands increases fast, the enforcement of a series of Huinong's policies such as the continuous quickening of new rural village Urbanization Construction process, particularly " household electrical appliances are gone to the countryside ", electricity for rural use and power load day, also benefit was soaring, and Rural Power Demand grows with each passing day.In rural power grids, in distribution low-voltage circuit, idle improvement is undesirable, the uneven situation of threephase load is serious, distribution capacity seriously overloads, and it is very serious that these all result in rural power grids low-voltage problem, constrains the development of rural economy.

In rural power grids, the uneven situation of threephase load is serious, often there will be single-phase load capacity and exceed distribution transformer capacity, and two-phase is the situation of underloading in addition, thus cause capacity of distribution transform not enough, low voltage; In rural power grids, reactive power compensation popularity rate is not high, even if power application capacitor is also because the problem such as harmonic wave causes capacitor fragile, cannot bringing normally into operation, and also to there is compensation precision not high for capacitor simultaneously, the problem that response speed is inadequate.

Summary of the invention

For the deficiency that prior art exists, the object of the invention is to provide a kind of imbalance and reactive power compensation integrated control system and method thereof, can improve the power factor of electric power system, rural power grids rate of qualified voltage and power supply reliability.

To achieve these goals, the present invention realizes by the following technical solutions:

A kind of imbalance of the present invention and reactive power compensation integrated control system, comprise as main control device general controller and multiple as controlled plant for receiving the compensation arrangement of main control device switching order; General controller, by detecting distribution transforming exit potential and electric current, calculates active power, reactive power, power factor (PF), rate of qualified voltage and tri-phase unbalance factor ε, thus controls described compensation arrangement switching; The compensation arrangement being connected on phase-alternate, for realizing active power in alternate transfer, is connected on compensation arrangement between phase-zero for reactive power compensation.

The control method of imbalance of the present invention and reactive power compensation integrated control system, specifically comprises following step:

(1) described general controller detects distribution transforming exit potential and electric current, and calculates active power, reactive power, power factor (PF), rate of qualified voltage and tri-phase unbalance factor ε;

(2) phase voltage U is judged _an, U _bn, U _cnwhether run off upper voltage limit U _uu, lower voltage limit U _dd:

If phase voltage U _an, U _bn, U _cnexceed upper voltage limit U _uu, then the compensation arrangement order between excision phase-zero is issued;

If phase voltage U _an, U _bn, U _cnlower than lower voltage limit U _dd, then the compensation arrangement order between input phase-zero is issued;

(3) if phase voltage U _an, U _bn, U _cnlimit U under voltage _ddwith upper voltage limit U _uuin scope, then judge that whether tri-phase unbalance factor ε is qualified;

If ε > is ε ₀represent tri-phase unbalance factor defective, then issue the compensation arrangement action command of phase-alternate according to imbalance compensation algorithm;

If ε≤ε ₀represent tri-phase unbalance factor qualified, then issue the compensation arrangement action command of compensation arrangement between phase-zero and phase-alternate according to Arithmetic for Reactive Power Compensation, wherein, ε ₀for the permission degree of unbalance of setting.

In step (3), described imbalance compensation algorithm concrete steps are as follows:

(a1) target function is set up: $H=I_a^2+I_b^2+I_c^2=\frac{P_a^2+Q_a^2}{U_a^2}+\frac{P_b^2+Q_b^2}{U_b^2}+\frac{P_c^2+Q_c^2}{U_c^2},$ Target function value H before calculation compensation ₀, wherein Ia, Ib, Ic, Ua, Ub, Uc represent distribution transforming outlet three-phase current and voltage; P _a, P _b, P _crepresent the active power that three-phase is total, Q _a, Q _b, Q _crepresent the reactive power that three-phase is total, total power comprises capacitive part and loading section;

(a2) can obtain according to principle of stacking:

$\left\{\begin{array}{c}{P}_a=\sqrt{3}(Q_{ca}^{\mathrm{\Δ}}-Q_{ab}^{\mathrm{\Δ}})/6+P_{aL}\\ P_b=\sqrt{3}(Q_{ab}^{\mathrm{\Δ}}-Q_{bc}^{\mathrm{\Δ}})/6+P_{bL}\\ P_c=\sqrt{3}(Q_{bc}^{\mathrm{\Δ}}-Q_{ca}^{\mathrm{\Δ}})/6+P_{cL}\\ Q_a=-(Q_{ab}^{\mathrm{\Δ}}+Q_{ca}^{\mathrm{\Δ}})/2-Q_a^Y+Q_{aL}\\ Q_b=-(Q_{ab}^{\mathrm{\Δ}}+Q_{bc}^{\mathrm{\Δ}})/2-Q_b^Y+Q_{bL}\\ Q_c=-(Q_{ca}^{\mathrm{\Δ}}+Q_{bc}^{\mathrm{\Δ}})/2-Q_c^Y+Q_{cL}\end{array}\right.$

Wherein, P _al, P _bL, P _cLrepresent the three phases active power of load, Q _aL, Q _bL, Q _cLrepresent the three phase reactive power of load, represent phase-alternate compensation arrangement capacity, represent phase-zero compensation arrangement capacity;

In reactive power compensation process, reactive power is the smaller the better, idlely draws following formula when being zero:

Set up relative phase-zero device and phase-alternate device relation;

(a3) because the capacity of multiple compensation arrangement is all get several discrete values, according to the constraints enumerative technique handle of step (a2) with value substitute into H, make H minimum, as the Switching Strategy of general controller.

In step (3), described Arithmetic for Reactive Power Compensation concrete steps are as follows:

(b1) the idle Switching Strategy of three-phase is calculated respectively with nine-zone diagram algorithm;

(b2) if the idle Switching Strategy of three-phase is identical, then select to control phase-alternate compensation arrangement switching;

(b3) Switching Strategy as idle in three-phase is different, then select to control phase-zero compensation arrangement and carry out switching compensation to three-phase respectively.

The present invention can improve the power factor of electric power system, reduces reactive current flowing, reduces power loss, improve the utilization rate of equipment; Reduce line voltage distribution loss, ensure the voltage stabilization of power supply-distribution system, improve the quality of power supply, improve the stability of system, be conducive to reasonable transmission and the application of electric power; Improve rural power grids rate of qualified voltage, power supply reliability.

Accompanying drawing explanation

Fig. 1 is a kind of imbalance of the present invention and reactive power compensation integrated Control system architecture block diagram.

Embodiment

The technological means realized for making the present invention, creation characteristic, reaching object and effect is easy to understand, below in conjunction with embodiment, setting forth the present invention further.

See Fig. 1, a kind of imbalance of the present invention and reactive power compensation integrated control system, comprise as main control device general controller and multiple as controlled plant for receiving the compensation arrangement of main control device switching order; General controller, by detecting distribution transforming exit potential and electric current, calculates active power, reactive power, power factor (PF), rate of qualified voltage and tri-phase unbalance factor ε, thus controls described compensation arrangement switching; The compensation arrangement being connected on phase-alternate, for realizing active power in alternate transfer, is connected on compensation arrangement between phase-zero for reactive power compensation.

The control method of imbalance of the present invention and reactive power compensation integrated control system, specifically comprises following step:

(1) described general controller detects distribution transforming exit potential and electric current, and calculates active power, reactive power, power factor (PF), rate of qualified voltage and tri-phase unbalance factor ε; In the present embodiment, phase voltage is 223V, and reactive power is 20KVAR, and power factor is 0.7, and tri-phase unbalance factor is 3%

(2) phase voltage U is judged _an, U _bn, U _cnwhether run off upper voltage limit U _uu, lower voltage limit U _dd:

If phase voltage U _an, U _bn, U _cnexceed upper voltage limit U _uu, then the compensation arrangement order between excision phase-zero is issued;

If phase voltage U _an, U _bn, U _cnlower than lower voltage limit U _dd, then the compensation arrangement order between input phase-zero is issued;

(3) if phase voltage U _an, U _bn, U _cnlimit U under voltage _ddwith upper voltage limit U _uuin scope, then judge that whether tri-phase unbalance factor ε is qualified;

If ε > is ε ₀represent tri-phase unbalance factor defective, then issue the compensation arrangement action command of phase-alternate according to imbalance compensation algorithm;

If ε≤ε ₀represent tri-phase unbalance factor qualified, then issue the compensation arrangement action command of compensation arrangement between phase-zero and phase-alternate according to Arithmetic for Reactive Power Compensation, wherein, ε ₀for the permission degree of unbalance of setting.

Because reactive power is 20KVAR, power factor is 0.7 eligible, then drop into capacitor.

In step (3), described imbalance compensation algorithm concrete steps are as follows:

(a1) target function is set up: $H=I_a^2+I_b^2+I_c^2=\frac{P_a^2+Q_a^2}{U_a^2}+\frac{P_b^2+Q_b^2}{U_b^2}+\frac{P_c^2+Q_c^2}{U_c^2},$ Target function value H before calculation compensation ₀, wherein Ia, Ib, Ic, Ua, Ub, Uc represent distribution transforming outlet three-phase current and voltage; P _a, P _b, P _crepresent the active power that three-phase is total, Q _a, Q _b, Q _crepresent the reactive power that three-phase is total, total power comprises capacitive part and loading section;

(a2) can obtain according to principle of stacking:

$\left\{\begin{array}{c}{P}_a=\sqrt{3}(Q_{ca}^{\mathrm{\Δ}}-Q_{ab}^{\mathrm{\Δ}})/6+P_{aL}\\ P_b=\sqrt{3}(Q_{ab}^{\mathrm{\Δ}}-Q_{bc}^{\mathrm{\Δ}})/6+P_{bL}\\ P_c=\sqrt{3}(Q_{bc}^{\mathrm{\Δ}}-Q_{ca}^{\mathrm{\Δ}})/6+P_{cL}\\ Q_a=-(Q_{ab}^{\mathrm{\Δ}}+Q_{ca}^{\mathrm{\Δ}})/2-Q_a^Y+Q_{aL}\\ Q_b=-(Q_{ab}^{\mathrm{\Δ}}+Q_{bc}^{\mathrm{\Δ}})/2-Q_b^Y+Q_{bL}\\ Q_c=-(Q_{ca}^{\mathrm{\Δ}}+Q_{bc}^{\mathrm{\Δ}})/2-Q_c^Y+Q_{cL}\end{array}\right.$

Wherein, P _al, P _bL, P _cLrepresent the three phases active power of load, Q _aL, Q _bL, Q _cLrepresent the three phase reactive power of load, represent phase-alternate compensation arrangement capacity, represent phase-zero compensation arrangement capacity;

In reactive power compensation process, reactive power is the smaller the better, idlely draws following formula when being zero:

$\left\{\begin{array}{c}{Q}_a^Y=Q_{aL}-(Q_{ab}^{\mathrm{\Δ}}+Q_{ca}^{\mathrm{\Δ}})/2\≥0\\ Q_b^Y=Q_{bL}-(Q_{ab}^{\mathrm{\Δ}}+Q_{bc}^{\mathrm{\Δ}})/2\≥0\\ Q_c^Y=Q_{cL}-(Q_{bc}^{\mathrm{\Δ}}+Q_{ca}^{\mathrm{\Δ}})/2\≥0\end{array}\right.$

Set up relative phase-zero device and phase-alternate device relation;

(a3) because the capacity of multiple compensation arrangement is all get several discrete values, according to the constraints enumerative technique handle of step (a2) with value substitute into H, make H minimum, as the Switching Strategy of general controller.

In step (3), described Arithmetic for Reactive Power Compensation concrete steps are as follows:

(b1) the idle Switching Strategy of three-phase is calculated respectively with nine-zone diagram algorithm;

(b2) if the idle Switching Strategy of three-phase is identical, then select to control phase-alternate compensation arrangement switching;

(b3) Switching Strategy as idle in three-phase is different, then select to control phase-zero compensation arrangement and carry out switching compensation to three-phase respectively.

More than show and describe general principle of the present invention and principal character and advantage of the present invention.The technical staff of the industry should understand; the present invention is not restricted to the described embodiments; what describe in above-described embodiment and specification just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.Application claims protection range is defined by appending claims and equivalent thereof.

Claims (4)

1. imbalance and a reactive power compensation integrated control system, is characterized in that, comprise as main control device general controller and multiple as controlled plant for receiving the compensation arrangement of main control device switching order;

Described general controller, by detecting distribution transforming exit potential and electric current, calculates active power, reactive power, power factor (PF), rate of qualified voltage and tri-phase unbalance factor ε, thus controls described compensation arrangement switching;

The compensation arrangement being connected on phase-alternate, for realizing active power in alternate transfer, is connected on compensation arrangement between phase-zero for reactive power compensation.

2. the control method of uneven and reactive power compensation integrated control system according to claim 1, is characterized in that, specifically comprise following step:

(1) described general controller detects distribution transforming exit potential and electric current, and calculates active power, reactive power, power factor (PF), rate of qualified voltage and tri-phase unbalance factor ε;

(2) phase voltage U is judged _an, U _bn, U _cnwhether run off upper voltage limit U _uu, lower voltage limit U _dd:

If phase voltage U _an, U _bn, U _cnexceed upper voltage limit U _uu, then the compensation arrangement order between excision phase-zero is issued;

If phase voltage U _an, U _bn, U _cnlower than lower voltage limit U _dd, then the compensation arrangement order between input phase-zero is issued;

(3) if phase voltage U _an, U _bn, U _cnlimit U under voltage _ddwith upper voltage limit U _uuin scope, then judge that whether tri-phase unbalance factor ε is qualified;

If ε > is ε ₀represent tri-phase unbalance factor defective, then issue the compensation arrangement action command of phase-alternate according to imbalance compensation algorithm;

If ε≤ε ₀represent tri-phase unbalance factor qualified, then issue the compensation arrangement action command of compensation arrangement between phase-zero and phase-alternate according to Arithmetic for Reactive Power Compensation, wherein, ε ₀for the permission degree of unbalance of setting.

3. the control method of uneven and reactive power compensation integrated control system according to claim 2, it is characterized in that, in step (3), described imbalance compensation algorithm concrete steps are as follows:

(a1) target function is set up: $H=I_a^2+I_b^2+I_c^2=\frac{P_a^2+Q_a^2}{U_a^2}+\frac{P_b^2+Q_b^2}{U_b^2}+\frac{P_c^2+Q_c^2}{U_c^2},$ Target function value H before calculation compensation ₀, wherein Ia, Ib, Ic, Ua, Ub, Uc represent distribution transforming outlet three-phase current and voltage; P _a, P _b, P _crepresent the active power that three-phase is total, Q _a, Q _b, Q _crepresent the reactive power that three-phase is total, total power comprises capacitive part and loading section;

(a2) can obtain according to principle of stacking:

$\left\{\begin{array}{c}{P}_a=\sqrt{3}(Q_{ca}^{\mathrm{\Δ}}-Q_{ab}^{\mathrm{\Δ}})/6+P_{aL}\\ P_b=\sqrt{3}(Q_{ab}^{\mathrm{\Δ}}-Q_{bc}^{\mathrm{\Δ}})/6+P_{bL}\\ P_c=\sqrt{3}(Q_{bc}^{\mathrm{\Δ}}-Q_{ca}^{\mathrm{\Δ}})/6+P_{cL}\\ Q_a=-(Q_{ab}^{\mathrm{\Δ}}+Q_{ca}^{\mathrm{\Δ}})/2-Q_a^Y+Q_{aL}\\ Q_b=-(Q_{ab}^{\mathrm{\Δ}}+Q_{bc}^{\mathrm{\Δ}})/2-Q_b^Y+Q_{bL}\\ Q_c=-(Q_{ca}^{\mathrm{\Δ}}+Q_{bc}^{\mathrm{\Δ}})/2-Q_c^Y+Q_{cL}\end{array}\right.$

Wherein, P _al, P _bL, P _cLrepresent the three phases active power of load, Q _aL, Q _bL, Q _cLrepresent the three phase reactive power of load, represent phase-alternate compensation arrangement capacity, represent phase-zero compensation arrangement capacity;

In reactive power compensation process, reactive power is the smaller the better, idlely draws following formula when being zero:

$\left\{\begin{array}{c}{Q}_a^Y=Q_{aL}-(Q_{ab}^{\mathrm{\Δ}}+Q_{ca}^{\mathrm{\Δ}})/2\≥0\\ Q_b^Y=Q_{bL}-(Q_{ab}^{\mathrm{\Δ}}+Q_{bc}^{\mathrm{\Δ}})/2\≥0\\ Q_c^Y=Q_{cL}-(Q_{bc}^{\mathrm{\Δ}}+Q_{ca}^{\mathrm{\Δ}})/2\≥0\end{array}\right.$

Set up relative phase-zero device and phase-alternate device relation;

(a3) because the capacity of multiple compensation arrangement is all get several discrete values, according to the constraints enumerative technique handle of step (a2) with value substitute into H, make H minimum, as the Switching Strategy of general controller.

4. the control method of uneven and reactive power compensation integrated control system according to claim 2, it is characterized in that, in step (3), described Arithmetic for Reactive Power Compensation concrete steps are as follows:

(b1) the idle Switching Strategy of three-phase is calculated respectively with nine-zone diagram algorithm;

(b2) if the idle Switching Strategy of three-phase is identical, then select to control phase-alternate compensation arrangement switching;

(b3) Switching Strategy as idle in three-phase is different, then select to control phase-zero compensation arrangement and carry out switching compensation to three-phase respectively.