CN104269903A - Energy management and optimization method based on super-capacitor terminal voltage precontrol - Google Patents

Abstract

Provided is an energy management and optimization method based on super-capacitor terminal voltage precontrol. The method comprises the steps that firstly, the fixed values of super-capacitor terminal voltage precontrol are set and comprise a high voltage out-of-limit fixed value Umax, a high voltage limit fixed value UUpSet, a low voltage out-of-limit fixed value Umin and a low voltage limit fixed value ULowSet, and the four fixed values divide a super-capacitor into five work areas, namely, a high voltage out-of-limit area, a high voltage limit area, a normal work area, a low voltage limit area and a low voltage out-of-limit area. Super-capacitor charge is limited and discharge is allowed in the high voltage out-of-limit area, charge is reduced and discharge is increased in the high voltage limit area to reduce the rise speed of super-capacitor terminal voltages, the power expectation of the super-capacitor is not adjusted in the normal work area, discharge is reduced and charge is increased in the low voltage limit area to reduce the reduction speed of the super-capacitor terminal voltages, and super-capacitor discharge is limited and charging is allowed in the low voltage out-of-limit area. According to the method, the on-network time of the super-capacitor can be prolonged, the control over a microgrid with the super-capacitor can be achieved conveniently, and the service life of the super-capacitor is prolonged.

Description

Based on the energy management optimization method that super capacitor terminal voltage controls in advance

Technical field

The invention belongs to electronic frequency convertor technical field, be specifically related to a kind of terminal voltage being applicable to super capacitor and control energy management optimization method in advance.

Background technology

In energy-storage system, super capacitor belongs to power-type energy storage device, power output excursion is large, rate of change is fast and charge and discharge cycles often, be mainly used to compensate the high-frequency fluctuation component in regenerative resource power output.

For preventing super capacitor and over-charging of battery from discharging, generally need to limit its charge-discharge electric power.Traditional control method reaches in limited time when super-capacitor voltage, limits charging and allows electric discharge; When super-capacitor voltage reaches in limited time lower, restriction electric discharge allows charging.Because super capacitor energy density is less, therefore its power output is larger, and output time is longer, and the energy of super capacitor more easily reaches minimax limit value, and its terminal voltage controls also easily to reach limit value in advance.Super capacitor terminal voltage controls too highly can reduce its useful life in advance, even punctures electric capacity, and its terminal voltage control in advance too low output current when exporting Same Efficieney can be caused excessive and cause overheated.Therefore, control in advance to carry out effectively management to be very necessary to the terminal voltage of super capacitor.

Summary of the invention

For overcoming the deficiency that existing super capacitor control method exists, the invention discloses the energy management optimization method controlled in advance based on super capacitor terminal voltage.

The present invention specifically adopts following technical scheme.

Based on the energy management optimization method that super capacitor terminal voltage controls in advance, it is characterized in that, said method comprising the steps of:

(1) first, the definite value that setting super capacitor terminal voltage controls in advance, comprises the out-of-limit definite value U of high pressure _max, high pressure limit formulation value U _upSet, the out-of-limit definite value U of low pressure _min, low voltage limit formulation value U _lowSet;

(2) the out-of-limit definite value U of high pressure set by step (1) _max, high pressure limit formulation value U _upSet, the out-of-limit definite value U of low pressure _min, low voltage limit formulation value U _lowSetthe working region of super capacitor is divided into 5 parts: the out-of-limit district of high pressure, high pressure restricted area, normal service area, low pressure restricted area, the out-of-limit district of low pressure;

(3) the terminal voltage U of super capacitor is detected _c, and by super capacitor terminal voltage U _cthe definite value controlled in advance with super capacitor terminal voltage set in step (1) compares;

(4) according to the comparative result of step (3), as super capacitor terminal voltage U _c>=U _max, described super capacitor is operated in the out-of-limit district of high pressure, forbids that super capacitor charges, and allows super capacitor electric discharge;

(5) according to the comparative result of step (3), as super capacitor terminal voltage U _cmeet U _upSet<U _c<U _max, described super capacitor is operated in high pressure restricted area (6), then need to reduce the super capacitor charging interval, increases discharge time, to slow down the speed that super capacitor terminal voltage rises; (6) according to the comparative result of step (3), as super capacitor terminal voltage U _cmeet U _lowSet≤ U _c≤ U _upSet, described super capacitor is operated in normal service area, and the power not adjusting super capacitor is expected;

(7) according to the comparative result of step (3), as super capacitor terminal voltage U _cmeet U _min<U _c<U _lowSet, described super capacitor is operated in low pressure restricted area, should reduce super capacitor discharge time, increases the super capacitor charging interval, to slow down the speed that super capacitor terminal voltage declines;

(8) according to the comparative result of step (3), as super capacitor terminal voltage U _c>=U _max, described super capacitor is in the out-of-limit district of low pressure, should forbid that super capacitor discharges, and allows super capacitor charging.

The present invention has following useful technique effect: can extend super capacitor in the net time, facilitate the control realization of the micro-capacitance sensor containing super capacitor greatly, extends the super capacitor life-span.

Accompanying drawing explanation

Fig. 1 is that super capacitor working region divides schematic diagram;

Fig. 2 is the energy management optimization method flow chart controlled in advance based on super capacitor terminal voltage;

Fig. 3 is the control of discharge figure controlled in advance based on super capacitor terminal voltage;

Fig. 4 is that the charging controlled in advance based on super capacitor terminal voltage controls.

Embodiment

Below in conjunction with Figure of description, technical scheme of the present invention is described in further details.

As shown in Figure 2 for the present invention is based on the energy management optimization method flow chart that super capacitor terminal voltage controls in advance, as shown in Figure 2, described energy control method comprises the following steps:

Step 1: first, the definite value that setting super capacitor terminal voltage controls in advance as shown in Figure 1, comprises the out-of-limit definite value U of high pressure _max(1), high pressure limit formulation value U _upSet(2), the out-of-limit definite value U of low pressure _min(3), low voltage limit formulation value U _lowSet(4).

Step 2: according to the definite value that terminal voltage controls in advance, super capacitor working region is divided into 5 parts: the out-of-limit district of high pressure (5), high pressure restricted area (6), normal service area (7), low pressure restricted area (8), the out-of-limit district of low pressure (9), as shown in Figure 1.

Step 3: according to detected super capacitor port voltage U _cwith the voltage in step 1 in advance control area judge super capacitor state-of-charge residing for which subregion in step 2;

Step 4: the subregion residing for the super capacitor calculated in step 3 and the power instruction of reception calculate the power after adjustment to expect as super capacitor terminal voltage U _c>=U _max, described super capacitor is operated in the out-of-limit district of high pressure (5), needs the charging of restriction super capacitor to allow electric discharge:

In this application, regulation power direction is just to flow out super capacitor, and namely the power expectation of super capacitor is during electric discharge during charging as super capacitor terminal voltage U _c>=U _max, do not allow charging only to allow electric discharge to realize super capacitor, namely time, according to super capacitor terminal voltage U _cpower after present working region adjustment is expected time, according to super capacitor terminal voltage U _cpower after present working region adjustment is expected power after electric discharge adjustment is expected discharge power is as shown in Equation 3:

$\left\{\begin{array}{cc}{P}_{\mathrm{Set}}^{*}=P_C^{*}& (P_C^{*}\&GreaterEqual;0)\\ P_{\mathrm{Set}}^{*}=0& (P_C^{*}<0)\end{array}\right.$ Formula (3)

Step 5: as super capacitor terminal voltage U _cmeet U _upSet<U _c<U _max, described super capacitor is operated in high pressure restricted area (6), then needing to reduce charging increases electric discharge, to slow down the speed that super capacitor terminal voltage rises

Slow down rate of voltage rise to be determined by voltage control coefficient k, for 1.Power direction is just to flow out super capacitor, and power is expected as shown in Equation 4:

$\left\{\begin{array}{cc}{P}_{\mathrm{Set}}^{*}=P_C^{*}\&times;(1+1\&times;\frac{U_C-U_{\mathrm{UpSet}}}{U_{\max }-U_{\mathrm{UpSet}}})& (P_C^{*}\&GreaterEqual;0)\\ P_{\mathrm{Set}}^{*}=P_C^{*}\&times;(1-1\&times;\frac{U_C-U_{\mathrm{UpSet}}}{U_{\max }-U_{\mathrm{UpSet}}})& (P_C^{*}<0)\end{array}\right.$ Formula (4)

Step 6: according to the comparative result of step (3), as super capacitor terminal voltage U _cmeet U _lowSet≤ U _c≤ U _upSet, described super capacitor is operated in normal service area (7), and the power not adjusting super capacitor is expected: namely power is expected as shown in Equation 5:

$P_{\mathrm{Set}}^{*}=P_C^{*}$ Formula (5)

Step 7: according to the comparative result of step (3), as super capacitor terminal voltage U _cmeet U _min<U _c<U _lowSet, described super capacitor is operated in low pressure restricted area (8), should reduce electric discharge and increase charging, to slow down the speed that super capacitor terminal voltage declines.Power after adjustment is expected as shown in Equation 6:

$\left\{\begin{array}{cc}{P}_{\mathrm{Set}}^{*}=P_C^{*}\&times;(1-1\&times;\frac{U_{\mathrm{LowSet}}-U_C}{U_{\mathrm{LowSet}}-U_{\min }})& (P_C^{*}\&GreaterEqual;0)\\ P_{\mathrm{Set}}^{*}=P_C^{*}\&times;(1+1\&times;\frac{U_{\mathrm{LowSet}}-U_C}{U_{\mathrm{LowSet}}-U_{\min }})& (P_C^{*}<0)\end{array}\right.$ Formula (6)

Step 8: according to the comparative result of step (3), as super capacitor terminal voltage U _c>=U _max, described super capacitor is in the out-of-limit district of low pressure (9), should limit super capacitor electric discharge and allow charging

The out-of-limit district of low pressure (9): super capacitor terminal voltage U _c>=U _max, the electric discharge of restriction super capacitor allows charging.Power direction is just to flow out super capacitor, and power is expected as shown in Equation 7:

$\left\{\begin{array}{cc}{P}_{\mathrm{Set}}^{*}=0& (P_C^{*}\&GreaterEqual;0)\\ P_{\mathrm{Set}}^{*}=P_C^{*}& (P_C^{*}<0)\end{array}\right.$ Formula (7)

Finally, the super capacitor discharge and recharge calculated according to the energy management optimization method controlled in advance based on super capacitor terminal voltage expects that power controls exerting oneself of super capacitor.

Fig. 3,4 be based on the above-mentioned steps of technical solution of the present invention control of discharge figure and charging control chart.

Applicant in conjunction with Figure of description to invention has been detailed description and description; but those skilled in the art should understand that; above embodiment is only the preferred embodiments of the invention; detailed explanation is just in order to help reader to understand spirit of the present invention better; and be not limiting the scope of the invention; on the contrary, any any improvement of doing based on invention of the present invention spirit or modify all should be within protection scope of the present invention.

Claims (4)

1., based on the energy management optimization method that super capacitor terminal voltage controls in advance, it is characterized in that:

The definite value that setting super capacitor terminal voltage controls in advance, is divided into different working regions according to definite value by super capacitor, adopts different charge and discharge control modes based on different working regions, optimize super capacitor energy management.

2., based on the energy management optimization method that super capacitor terminal voltage controls in advance, it is characterized in that, said method comprising the steps of:

(1) first, the definite value that setting super capacitor terminal voltage controls in advance, comprises the out-of-limit definite value U of high pressure _max, high pressure limit formulation value U _upSet, the out-of-limit definite value U of low pressure _min, low voltage limit formulation value U _lowSet;

(2) the out-of-limit definite value U of high pressure set by step (1) _max, high pressure limit formulation value U _upSet, the out-of-limit definite value U of low pressure _min, low voltage limit formulation value U _lowSetthe working region of super capacitor is divided into 5 parts: the out-of-limit district of high pressure, high pressure restricted area, normal service area, low pressure restricted area, the out-of-limit district of low pressure;

(3) the terminal voltage U of super capacitor is detected _c, and by super capacitor terminal voltage U _cthe definite value controlled in advance with super capacitor terminal voltage set in step (1) compares;

(4) according to the comparative result of step (3), as super capacitor terminal voltage U _c>=U _max, described super capacitor is operated in the out-of-limit district of high pressure, forbids that super capacitor charges, and allows super capacitor electric discharge;

(5) according to the comparative result of step (3), as super capacitor terminal voltage U _cmeet U _upSet<U _c<U _max, described super capacitor is operated in high pressure restricted area, then need to reduce super capacitor charging, increases electric discharge, to slow down the speed that super capacitor terminal voltage rises;

(6) according to the comparative result of step (3), as super capacitor terminal voltage U _cmeet U _lowSet≤ U _c≤ U _upSet, described super capacitor is operated in normal service area, and the power not adjusting super capacitor is expected;

(7) according to the comparative result of step (3), as super capacitor terminal voltage U _cmeet U _min<U _c<U _lowSet, described super capacitor is operated in low pressure restricted area, should reduce super capacitor discharge time, increases the super capacitor charging interval, to slow down the speed that super capacitor terminal voltage declines;

(8) according to the comparative result of step (3), as super capacitor terminal voltage U _c>=U _max, described super capacitor is in the out-of-limit district of low pressure, should forbid that super capacitor discharges, and allows super capacitor charging.

3. energy management optimization method according to claim 2, is characterized in that:

In step (5), the power expectation after discharge and recharge adjustment is shown in following 1:

$\left\{\begin{array}{c}{P}_{\mathrm{Set}}^{*}=P_C^{*}\&times;(1+k\&times;\frac{U_C-U_{\mathrm{UpSet}}}{U_{\max }-U_{\mathrm{UpSet}}})(P_C^{*}\&GreaterEqual;0)\\ P_{\mathrm{Set}}^{*}=P_C^{*}\&times;(1-k\&times;\frac{U_C-U_{\mathrm{UpSet}}}{U_{\max }-U_{\mathrm{UpSet}}})(P_C^{*}<0)\end{array}\right.$ Formula (1)

In formula: the power received for super capacitor is expected, for the power after super capacitor discharge and recharge adjustment is expected, U _cfor super capacitor port voltage, U _maxfor the out-of-limit definite value of super capacitor high pressure, U _upSetfor super capacitor high pressure limit formulation value, 0≤k≤1.

4. energy management optimization method according to claim 2, is characterized in that:

In step (7), the power expectation after discharge and recharge adjustment is shown in 2:

$\left\{\begin{array}{c}{P}_{\mathrm{Set}}^{*}=P_C^{*}\&times;(1-k\&times;\frac{U_{\mathrm{LowSet}}-U_C}{U_{\mathrm{LowSet}}-U_{\min }})(P_C^{*}\&GreaterEqual;0)\\ P_{\mathrm{Set}}^{*}=P_C^{*}\&times;(1+k\&times;\frac{U_{\mathrm{LowSet}}-U_C}{U_{\mathrm{LowSet}}-U_{\min }})(P_C^{*}<0)\end{array}\right.$ Formula (2)

In formula: the power received for super capacitor is expected, for the power after super capacitor discharge and recharge adjustment is expected, U _cfor super capacitor port voltage, U _lowSetfor super capacitor low voltage limit formulation value, U _minfor the out-of-limit definite value of super capacitor low pressure, 0≤k≤1.