CN103346570A - Solar photovoltaic power generation dynamic voltage compensator with energy storage function - Google Patents

Abstract

The invention discloses a solar photovoltaic power generation dynamic voltage compensator with an energy storage function. The solar photovoltaic power generation dynamic voltage compensator comprises a solar photovoltaic cell panel, a direct-current boost unit, an inversion unit, an energy storage unit and a transformer. The solar photovoltaic cell panel converts solar energy to electric energy to be output, two input ends of the direct-current boost unit are connected with two output ends of the solar photovoltaic cell panel, two input ends of the inversion unit are connected with two output ends of the direct-current boost unit, the two ends of the energy storage unit are respectively connected to a connecting electric wire between the direct-current boost unit and the inversion unit, a primary coil of the transformer is connected with an output end of the inversion unit, and a secondary coil of the transformer is used for being connected in series to a power grid in series. The solar photovoltaic power generation dynamic voltage compensator with the energy storage function can carry out voltage compensation when the voltage of the power grid drops.

Description

A kind of dynamic voltage compensator with solar energy power generating of energy-storage function

Technical field

The present invention relates to a kind of voltage compensating device, relate in particular to a kind of voltage compensating device of solar energy power generating.

Background technology

Along with developing rapidly of China's high-technology industry, the user is also more and more higher to the requirement of quality of power supply level, power quality problem not only can bring very big economic loss to industrial quarters, cause production cost to increase as stopping work and restarting, the damage equipment that is quick on the draw, scrap semi-finished product, reduce product quality, cause marketing difficulty and the infringement corporate image and and user's good commercial relations etc., and bring harm can for the equipment of important electricity consumption such as medical treatment department, cause serious production and interruption of service.

In power quality problem, it is one of sixty-four dollar question that voltage falls, and voltage falls the quality of voltage problem that not only can cause electric power system, the also trouble free service of entail dangers to power consumption equipment.Electric power system fault, large-size machine starts, subcircuits short circuit etc. can cause that all voltage falls, though the voltage drop-out time is short, but it can cause interruption or the shut-down of industrial process, and cause industrial process downtime be far longer than of voltage fallen accident itself time, therefore the loss that causes is very big.The feature that voltage falls is that line voltage drops to 10% to 90% normal voltage value suddenly and continues 0.5 to 50 cycle, the change in voltage amplitude that most voltages fall in 50%, and the duration be no more than 500 milliseconds.

Existing some device can not solve above-mentioned voltage as voltage regulator and fall problem, though and uninterrupted power supply UPS device can address these problems, but its cost and operating cost are all extremely expensive.

Summary of the invention

The purpose of this invention is to provide a kind of dynamic voltage compensator with solar energy power generating of energy-storage function; it utilizes solar power generation and the voltage in the electrical network is fallen and compensates; at electrical network just often; it can be electrical power storage with conversion of solar energy; and when occurring voltage in the electrical network and fall; its output voltage is with the difference of compensation network voltage, thereby guarantees that load voltage does not change, and then protected load.

In order to achieve the above object, the invention provides a kind of dynamic voltage compensator with solar energy power generating of energy-storage function, it comprises:

One solar photovoltaic cell panel is with conversion of solar energy to be electric energy output;

One direct current boosting unit, two input is connected with two outputs of described solar photovoltaic cell panel;

One inversion unit, two input is connected with two outputs of described DC boosting unit;

One energy-storage units, its two ends are connected on the connection electric wire between described DC boosting unit and the inversion unit;

One transformer, its primary coil is connected with the output of inversion unit, and the secondary coil of described transformer is in order to being serially connected in the electrical network, thereby links to each other with load side with the common port of electrical network respectively.

In the dynamic voltage compensator of above-mentioned solar energy power generating with energy-storage function, the capacity S of described inversion unit _{R, l}Satisfy:

$S_{r,l}\≥\sqrt{P_i^2+Q_i^2}$

In the formula, P _iThe active power of expression dynamic voltage compensator output, Q _iThe reactive power of expression dynamic voltage compensator output.

Suppose that line voltage is

Load voltage is

The described dynamic voltage compensator of the technical program is to the electrical network injecting voltage so

With line voltage

And load voltage

Between relation be shown below:

${\stackrel{\‾}{V}}_L={\stackrel{\‾}{V}}_i+{\stackrel{\‾}{E}}_S-{\stackrel{\‾}{Z}}_S{\stackrel{\‾}{I}}_i---\left(1\right)$

Wherein,

Be the electric network source equivalent impedance,

Be the electric current that dynamic voltage compensator injects to electrical network, "-" represents to quantity symbol.

If load meter is shown: (P wherein _LAnd Q _LActive power and the reactive power of representing load respectively)

${\stackrel{\‾}{S}}_L=P_L+j{Q}_L---\left(2\right)$

If The expression load current, then

${\stackrel{\‾}{V}}_L\·{\stackrel{\‾}{I}}_L^{*}=P_L+j{Q}_L---\left(3\right)$

${\stackrel{\‾}{V}}_i\·{\stackrel{\‾}{I}}_i^{*}=P_i+j{Q}_i---\left(4\right)$

In the following formula,

For

Conjugate,

For

Conjugate.

Load current and dynamic voltage compensator inject electric current to electrical network and are respectively:

${\stackrel{\‾}{I}}_L=\frac{P_L-j{Q}_L}{{\stackrel{\‾}{V}}_L^{*}}---\left(5\right)$

${\stackrel{\‾}{I}}_i=\frac{P_i-j{Q}_i}{{\stackrel{\‾}{V}}_i^{*}}---\left(6\right)$

Because dynamic voltage compensator of the present invention is serially connected with in the electrical network, therefore, the electric current that dynamic voltage compensator injects to electrical network

Should with load current

Equate, namely

According to above-mentioned (5) (6) two formulas, can get

${\stackrel{\‾}{V}}_i=\frac{P_i+j{Q}_i}{P_L+j{Q}_L}{\stackrel{\‾}{V}}_L---\left(7\right)$

With above-mentioned formula (7) substitution (1), can get

$V_L^2[(P_L-P_i)+j(Q_L-Q_i)]={\stackrel{\‾}{E}}_S{\stackrel{\‾}{V}}_L^{*}(P_L+j{Q}_L)-{\stackrel{\‾}{Z}}_S{S}_L^2---\left(8\right)$

Above-mentioned (8) formula real part, imaginary part equate respectively, can get:

$\left.\begin{array}{c}{V}_L^2(P_L-P_i)+(-E_S{P}_L{V}_L\mathrm{Cos\θ}-E_S{Q}_L{V}_L\mathrm{Sin\θ})+R_S{S}_L^2=0\\ V_L^2(Q_L-Q_i)+(-E_S{Q}_L{V}_L\mathrm{Cos\θ}+E_S{P}_L{V}_L\mathrm{Sin\θ})+X_S{S}_L^2=0\end{array}\right\}---\left(9\right)$

Wherein, θ is the load voltage phase angle, V _LBe load voltage amplitude, R _SWith X _SBe respectively circuit equivalent resistance and reactance.

Formula (9) shows: by regulating the active power P of dynamic voltage compensator output _iWith reactive power Q _i, can keep the constant of load voltage phase angle and amplitude.

Further, in the dynamic voltage compensator of above-mentioned solar energy power generating with energy-storage function, described energy-storage units comprises battery, and electrical power storage is in battery.

As a kind of execution mode, energy-storage units in the technical program comprises: battery, inductance, IGBT, diode and dc capacitor, wherein, the positive pole of battery links to each other with the emitter of IGBT, the negative pole of battery links to each other with the positive polarity output of energy-storage units, the collector electrode of IGBT, one end of the negative electrode of diode and inductance links together, the anode of diode links to each other with the voltage cathode output end of energy-storage units, the other end of inductance is connected with the positive polarity output of energy-storage units, dc capacitor is attempted by between the positive polarity output and voltage cathode output end of energy-storage units, and the positive polarity output of energy-storage units and voltage cathode output end are connected on the connection electric wire between DC boosting unit and the inversion unit.

Energy-storage units in the technical program can also comprise super capacitor, and it is used for store electrical energy.

As another kind of execution mode, energy-storage units in the technical program comprises: super capacitor, inductance, IGBT, diode and dc capacitor, wherein, the positive pole of super capacitor links to each other with the emitter of IGBT, the negative pole of super capacitor links to each other with the positive polarity output of energy-storage units, the collector electrode of IGBT, one end of the negative electrode of diode and inductance links together, the anode of diode links to each other with the voltage cathode output end of energy-storage units, the other end of inductance is connected with the positive polarity output of energy-storage units, dc capacitor is attempted by between the positive polarity output and voltage cathode output end of energy-storage units, and the positive polarity output of described energy-storage units and voltage cathode output end are connected on the connection electric wire between DC boosting unit and the inversion unit.

Further, in the dynamic voltage compensator of above-mentioned solar energy power generating with energy-storage function, described DC boosting unit comprises: the DC boosting inductance, IGBT, diode and dc capacitor, wherein the positive polarity input of DC boosting unit links to each other with an end of DC boosting inductance, the voltage negative input of DC boosting unit is connected with the collector electrode of IGBT, the emitter of IGBT, the other end of DC boosting inductance and the anode of diode link together, the negative electrode of diode is connected with the cathode output end of DC boosting unit, the collector electrode of IGBT is connected with the cathode output end of DC boosting unit, and dc capacitor is connected between the cathode output end and cathode output end of DC boosting unit.

Further, in the dynamic voltage compensator of above-mentioned solar energy power generating with energy-storage function, described inversion unit comprises three-phase, every is a H bridge construction mutually, described each H bridge construction includes four IGBT, the direct-flow input end of each H bridge all is connected with two outputs of DC boosting unit, and the ac output end of each H bridge is connected with the two ends of transformer.

The dynamic voltage compensator of the solar energy power generating with energy-storage function of the present invention has the following advantages compared to prior art:

1) effectively utilized solar energy;

2) can effectively solve line voltage and fall problem, thus the protection load;

3) when voltage not taking place fall, can carry out energy storage.

Description of drawings

Fig. 1 is the structural representation of dynamic voltage compensator under a kind of execution mode with solar energy power generating of energy-storage function of the present invention.

Fig. 2 is the voltage compensating principle schematic diagram of the dynamic voltage compensator of the solar energy power generating with energy-storage function of the present invention.

Fig. 3 is the voltage compensation analogous diagram of dynamic voltage compensator when voltage falls with solar energy power generating of energy-storage function of the present invention.

Fig. 4 is active power and the reactive power output analogous diagram of dynamic voltage compensator when voltage falls with solar energy power generating of energy-storage function of the present invention.

Fig. 5 is the topology diagram of the dynamic voltage compensator DC boosting cells D C/DC in one embodiment of the solar energy power generating with energy-storage function of the present invention.

Fig. 6 is the topology diagram of the dynamic voltage compensator energy-storage units in one embodiment of the solar energy power generating with energy-storage function of the present invention.

Fig. 7 is the topology diagram of the dynamic voltage compensator energy-storage units in another embodiment of the solar energy power generating with energy-storage function of the present invention.

Fig. 8 is the topology diagram of the phase among the dynamic voltage compensator inversion unit DC/AC in one embodiment of the solar energy power generating with energy-storage function of the present invention.

Embodiment

Below will be described further the dynamic voltage compensator with solar energy power generating of energy-storage function of the present invention according to specific embodiment and Figure of description, but this explanation does not constitute improper restriction of the present invention.

Fig. 1 has shown a kind of embodiment of the dynamic voltage compensator of the solar energy power generating with energy-storage function of the present invention.

As shown in Figure 1, this dynamic voltage compensator comprises: solar photovoltaic cell panel PV, it is electric energy P with conversion of solar energy _PVExport to DC boosting cells D C/DC; Two inputs of DC boosting cells D C/DC are connected with two outputs of solar photovoltaic cell panel PV, and two output is connected with two inputs of inversion unit DC/AC; Energy-storage units ESS is connected between two inputs (also being two outlet lines of DC boosting unit) of inversion unit DC/AC; The output of inversion unit DC/AC is connected in series with the primary coil of transformer, and the secondary coil of transformer is serially connected in the electrical network, links to each other with load side with the common port of electrical network respectively.

Need to prove in addition, those skilled in the art should know AC transformer and have three-phase, therefore the output of the inversion unit in the technical program is connected with the primary coil of transformer, refers to the output of each phase in the inversion unit and the corresponding connection of primary coil of each phase of transformer.

Among Fig. 1, the line voltage of electrical network is

Load voltage is

Dynamic voltage compensator in the present embodiment is to the electrical network injecting voltage

With line voltage

And load voltage Between relation be shown below:

${\stackrel{\‾}{V}}_L={\stackrel{\‾}{V}}_i+{\stackrel{\‾}{E}}_S-{\stackrel{\‾}{Z}}_S{\stackrel{\‾}{I}}_i---\left(1\right)$

Wherein,

Be the electric network source equivalent impedance,

Be the electric current of dynamic voltage compensator to the electrical network injection.

If load meter is shown: (P wherein _LAnd Q _LActive power and the reactive power of representing load respectively)

${\stackrel{\‾}{S}}_L=P_L+j{Q}_L---\left(2\right)$

If

The expression load current, then

${\stackrel{\‾}{V}}_L\·{\stackrel{\‾}{I}}_L^{*}=P_L+j{Q}_L---\left(3\right)$

${\stackrel{\‾}{V}}_i\·{\stackrel{\‾}{I}}_i^{*}=P_i+j{Q}_i---\left(4\right)$

Wherein,

For

Conjugate,

For Conjugate, P _iThe active power of expression dynamic voltage compensator output, Q _iThe reactive power of expression dynamic voltage compensator output.

Load current and dynamic voltage compensator inject electric current to electrical network and are respectively:

${\stackrel{\‾}{I}}_L=\frac{P_L-j{Q}_L}{{\stackrel{\‾}{V}}_L^{*}}---\left(5\right)$

${\stackrel{\‾}{I}}_i=\frac{P_i-j{Q}_i}{{\stackrel{\‾}{V}}_i^{*}}---\left(6\right)$

Because dynamic voltage compensator of the present invention is serially connected with in the electrical network, therefore, the electric current that dynamic voltage compensator injects to electrical network

Should with load current

Equate, namely

According to above-mentioned (5) (6) two formulas, can get

${\stackrel{\‾}{V}}_i=\frac{P_i+j{Q}_i}{P_L+j{Q}_L}{\stackrel{\‾}{V}}_L---\left(7\right)$

With above-mentioned formula (7) substitution (1), can get

$V_L^2[(P_L-P_i)+j(Q_L-Q_i)]={\stackrel{\‾}{E}}_S{\stackrel{\‾}{V}}_L^{*}(P_L+j{Q}_L)-{\stackrel{\‾}{Z}}_S{S}_L^2---\left(8\right)$

Above-mentioned (8) formula real part, imaginary part equate respectively, can get:

$\left.\begin{array}{c}{V}_L^2(P_L-P_i)+(-E_S{P}_L{V}_L\mathrm{Cos\θ}-E_S{Q}_L{V}_L\mathrm{Sin\θ})+R_S{S}_L^2=0\\ V_L^2(Q_L-Q_i)+(-E_S{Q}_L{V}_L\mathrm{Cos\θ}+E_S{P}_L{V}_L\mathrm{Sin\θ})+X_S{S}_L^2=0\end{array}\right\}---\left(9\right)$

Wherein, θ is the load voltage phase angle, V _LBe load voltage amplitude, R _SWith X _SBe respectively circuit equivalent resistance and reactance.

Formula (9) shows, by regulating the active power P of dynamic voltage compensator output _iWith reactive power Q _i, can keep the constant of load voltage phase angle and amplitude.

In the present embodiment, the capacity S of inversion unit _{R, l}Satisfy:

Fig. 2 has shown the voltage compensating principle schematic diagram of dynamic voltage compensator.Fig. 2 with For with reference to the injecting voltage that drawn

Common point PCC busbar voltage among Fig. 1

Load voltage

Load current

Wait the relation between each vector, as can be seen from Figure 2, according to line voltage

Dynamic voltage compensator of the present invention is to the electrical network injecting voltage Obtain the required voltage of loading

Analogous diagram when Fig. 3 falls for line voltage, when electric network fault caused that line voltage falls, dynamic voltage compensator of the present invention injected line voltage

Make amplitude and the phase angle of load voltage not influenced by electric network fault, when solar energy was arranged, DC bus-bar voltage was unaffected, and when the solar energy deficiency or night electrical network break down when needing protection load, then need to rely on the energy storage of energy-storage units.

Fig. 4 has shown dynamic voltage compensator active power of output P of the present invention when voltage falls _iWith reactive power Q _iWaveform.

Fig. 5 is the topology diagram that has shown the dynamic voltage compensator DC boosting cells D C/DC in one embodiment of the solar energy power generating with energy-storage function of the present invention.

As shown in Figure 5, in this embodiment, the DC boosting unit comprises: the DC boosting inductance, IGBT, diode and dc capacitor, the positive polarity input of DC boosting unit links to each other with an end of DC boosting inductance, the voltage negative input of DC boosting unit is connected with the collector electrode of IGBT, the emitter of IGBT, the other end of DC boosting inductance and the anode of diode link together, the negative electrode of diode is connected with the cathode output end of DC boosting unit, the collector electrode of IGBT is connected with the cathode output end of DC boosting unit, and dc capacitor is connected between the cathode output end and cathode output end of DC boosting unit.

Fig. 6 has shown the topology diagram of the dynamic voltage compensator energy-storage units in one embodiment of the solar energy power generating with energy-storage function of the present invention.

As shown in Figure 6, in this embodiment, energy-storage units comprises: battery, inductance, IGBT, diode and dc capacitor, the positive pole of battery links to each other with the emitter of IGBT, the negative pole of battery links to each other with the positive polarity output of energy-storage units, the collector electrode of IGBT, one end of the negative electrode of diode and inductance links together, the anode of diode links to each other with the voltage cathode output end of energy-storage units, the other end of inductance is connected with the positive polarity output of energy-storage units, dc capacitor is attempted by between the positive polarity output and voltage cathode output end of energy-storage units, and the positive polarity output of energy-storage units and voltage cathode output end are connected on the connection electric wire between DC boosting unit and the inversion unit.

Fig. 7 has shown the topology diagram of the dynamic voltage compensator energy-storage units in another embodiment of the solar energy power generating with energy-storage function of the present invention.As shown in Figure 7, in this embodiment, the structure of energy-storage units and structure shown in Figure 6 there is no big difference, have just changed battery into super capacitor.

Fig. 8 has shown the topology diagram of the phase among the dynamic voltage compensator inversion unit DC/AC in one embodiment of the solar energy power generating with energy-storage function of the present invention.As shown in Figure 8, each of inversion unit is the H bridge construction that four IGBT constitute mutually.

It should be noted that above cited embodiment only is specific embodiments of the invention.Obviously the present invention is not limited to above embodiment, and the similar variation of thereupon making or distortion are that those skilled in the art can directly draw or be easy to and just associate from content disclosed by the invention, all should belong to protection scope of the present invention.

Claims (8)

1. dynamic voltage compensator with solar energy power generating of energy-storage function, it comprises:

One solar photovoltaic cell panel is with conversion of solar energy to be electric energy output;

One direct current boosting unit, two input is connected with two outputs of described solar photovoltaic cell panel;

One inversion unit, two input is connected with two outputs of described DC boosting unit;

One energy-storage units, its two ends are connected on the connection electric wire between described DC boosting unit and the inversion unit;

One transformer, its primary coil is connected with the output of inversion unit, and the secondary coil of described transformer is in order to be serially connected in the electrical network.

2. dynamic voltage compensator as claimed in claim 1 is characterized in that, the capacity S of described inversion unit _{R, l}Satisfy:

$S_{r,l}\≥\sqrt{P_i^2+Q_i^2}$

In the formula, P _iThe active power of expression dynamic voltage compensator output, Q _iThe reactive power of expression dynamic voltage compensator output.

3. dynamic voltage compensator as claimed in claim 1 is characterized in that, described energy-storage units comprises battery.

4. dynamic voltage compensator as claimed in claim 3, it is characterized in that, described energy-storage units also comprises: inductance, IGBT, diode and dc capacitor, wherein, the positive pole of battery links to each other with the emitter of IGBT, the negative pole of battery links to each other with the positive polarity output of energy-storage units, the collector electrode of IGBT, one end of the negative electrode of diode and inductance links together, the anode of diode links to each other with the voltage cathode output end of energy-storage units, the other end of inductance is connected with the positive polarity output of energy-storage units, dc capacitor is attempted by between the positive polarity output and voltage cathode output end of energy-storage units, and the positive polarity output of described energy-storage units and voltage cathode output end are connected on the connection electric wire between DC boosting unit and the inversion unit.

5. dynamic voltage compensator as claimed in claim 1 is characterized in that, described energy-storage units comprises super capacitor.

6. dynamic voltage compensator as claimed in claim 5, it is characterized in that, described energy-storage units also comprises: inductance, IGBT, diode and dc capacitor, wherein, the positive pole of super capacitor links to each other with the emitter of IGBT, the negative pole of super capacitor links to each other with the positive polarity output of energy-storage units, the collector electrode of IGBT, one end of the negative electrode of diode and inductance links together, the anode of diode links to each other with the voltage cathode output end of energy-storage units, the other end of inductance is connected with the positive polarity output of energy-storage units, dc capacitor is attempted by between the positive polarity output and voltage cathode output end of energy-storage units, and the positive polarity output of described energy-storage units and voltage cathode output end are connected on the connection electric wire between DC boosting unit and the inversion unit.

7. dynamic voltage compensator as claimed in claim 1, it is characterized in that, described DC boosting unit comprises: the DC boosting inductance, IGBT, diode and dc capacitor, wherein the positive polarity input of DC boosting unit links to each other with an end of DC boosting inductance, the voltage negative input of DC boosting unit is connected with the collector electrode of IGBT, the emitter of IGBT, the other end of DC boosting inductance and the anode of diode link together, the negative electrode of diode is connected with the cathode output end of DC boosting unit, the collector electrode of IGBT is connected with the cathode output end of DC boosting unit, and dc capacitor is connected between the cathode output end and cathode output end of DC boosting unit.

8. dynamic voltage compensator as claimed in claim 1, it is characterized in that, described inversion unit comprises three-phase, every is a H bridge construction mutually, described each H bridge construction includes four IGBT, the direct-flow input end of each H bridge all is connected with two outputs of DC boosting unit, and the ac output end of each H bridge is connected with the two ends of transformer.

Images