CN102904485A - Electric energy quality serial compensator based on solar photovoltaic power generation - Google Patents

Abstract

The invention relates to an electric energy quality serial compensator based on solar photovoltaic power generation. The electric energy quality serial compensator is composed of a solar photovoltaic battery plate, a direct current boosting unit (DC (direct current) /DC), an inversion unit (DC/AC (alternating current)) and a serial transformer, and is connected in series with an electric network, wherein when the electric network is in a normal operation, the electric energy quality compensator can convert solar energy into electrical energy, and the output power is supplied for a load; and when the electric network goes wrong so as to cause an electric network voltage to rapidly fall (downfall, dropping) or rapidly increase (surging), the electric energy quality compensator outputs the corresponding compensating voltage quantity, and the voltage of a load end is kept constant, so that the load is protected from being influenced by the electric network fault, and the solar energy is utilized to solve the energy storage problem of a traditional serial compensator. The electric energy quality serial compensator provided by the invention utilizes solar energy to generate power and store energy, and meanwhile can be used for solving the voltage dip and rapid increasing problem and improving the electric energy quality characteristic.

Description

A kind of quality of power supply series compensator based on solar energy power generating

Technical field

The present invention relates to quality of power supply technical field, particularly a kind of quality of power supply technology based on solar power generation.

Background technology

Developed country is very high to the requirement of quality of power supply level, power quality problem not only can bring very large 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 the important electricity consumption such as medical treatment department, cause serious production and interruption of service, EPRI-Electric Power Research Institute (EPRI) studies show that, power quality problem causes American industry in data every year, and the loss on material and the productivity reaches 30,000,000,000 dollars (Electric Power Research Institute, 1999), in Singapore, each voltage instantaneous descends all can cause the economic loss that surpasses 1,000,000 Singapore dollars; Along with developing rapidly of China's high-technology industry, requirement to quality of power supply level is also more and more higher, voltage collapse (is subside, fall) and rise sharply (surge) be wherein subject matter, voltage is subside the quality of voltage problem that not only can cause electric power system with surge, 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 subsides, voltage surge is by lightning, connecting electric power system and other reasons causes overvoltage to cause, large-size machine and air conditioner are that large voltage surge produces the source, although it is short that voltage was subside with the surge time, but it can cause interruption or the shut-down of industrial process, and cause industrial process downtime be far longer than voltage and subside itself with the surge accident time, therefore the loss that causes is very large, the feature that voltage is subside is that supply voltage suddenly drops to 10% to 90% normal voltage value and continues 0.5 to 50 cycle, the feature of voltage surge is that supply voltage suddenly rises to 110% to 180% normal voltage value and continues 0.5 to 50 cycle, overwhelming majority voltage is subside and surge, its change in voltage amplitude in 50%, and the duration be no more than 500 milliseconds;

Traditional method, can not address these problems such as voltage regulator and surge suppressor, though and uninterrupted power supply UPS device can address these problems, but its cost and operating cost are all extremely expensive, in order to address the above problem, dynamic voltage compensator has been carried out research both at home and abroad.Than UPS, dynamic voltage compensator can solve effectively that voltage is subside, the problem of surge.But the energy storage problem is also perplexing the problem of dynamic voltage compensator always, although there is the people to propose the advanced methods such as least energy injection method, extra energy storage affects all the time it and further promotes, develops.

Summary of the invention

For the problems referred to above, the purpose of this invention is to provide a kind of quality of power supply series compensator based on solar energy power generating, it takes full advantage of solar energy, and when electrical network was normal, it utilized green solar energy, and solar energy is converted to electric energy, supplied with load; When line voltage breaks down, as subside or during surge, it exports corresponding voltage, the difference of compensation network voltage is guaranteed that load voltage does not change, thereby has been protected load.

Technical solution of the present invention is as follows:

A kind of quality of power supply series compensator based on solar energy power generating, characteristics are that its formation comprises solar photovoltaic cell panel, DC boosting unit, inversion unit and series transformer;

The annexation of above-mentioned parts is as follows:

Described solar photovoltaic cell panel is converted to electric energy with solar energy, two electric wires of its dc voltage output end link to each other with two electric wires of the direct-flow input end of described DC boosting unit, between two electric wires of the input of this DC boosting unit and connect a direct current electric capacity, two electric wires of the output of described DC boosting unit link to each other with two electric wires of the direct-flow input end of described inversion unit, between two electric wires of the direct-flow input end of this inversion unit and connect a direct current electric capacity, two electric wires of the ac output end of described inversion unit link to each other with the two ends of the primary coil of described series transformer, the secondary coil of described series transformer is serially connected in the power transmission line of electrical network, links to each other with load side with the common port of electrical network respectively.

The principle of the invention is as follows:

Supply voltage

Load voltage

Described quality of power supply series compensator is to the electrical network injecting voltage

Relations Among is 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,

For described quality of power supply series compensator to the electrical network Injection Current, "-" is to quantity symbol.

Load meter is shown: ${\stackrel{\‾}{S}}_L=P_L+j{Q}_L---\left(2\right)$ If

Be 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, subscript in the literary composition " * " is conjugate of symbol.

Load current and described quality of power supply series compensator are respectively to the electrical network Injection Current:

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

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

5 because described quality of power supply series compensator is serially connected with in the electrical network, and therefore, described quality of power supply series compensator is to the electric current of electrical network injection

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 the load voltage amplitude;

Formula (9) shows: by regulating the active-power P of described quality of power supply series compensator output _iWith reactive power Q _i, can keep the constant of load voltage phase angle and amplitude;

The capacity S of described inversion unit _{R, l}Must meet following relationship:

$S_{r,l}\≥\sqrt{P_i^2+Q_i^2}---\left(10\right)$

Compared with prior art, characteristics of the present invention are as follows:

1. utilize solar energy, not only environmental protection, but also solved the problem of Voltage Series compensation energy storage;

2. solve line voltage and subside the problem of (rapid drawdown, fall) and surge (rising sharply), protected important load;

3. when electrical network is normal, solar energy is converted to electric energy, load is given in power supply.

Description of drawings

Fig. 1 is the structural representation of a kind of quality of power supply series compensator based on solar energy power generating of the present invention.

Fig. 2 is voltage compensating principle schematic diagram of the present invention.

Fig. 3 is that line voltage of the present invention is subside the voltage compensation analogous diagram.

Fig. 4 is that line voltage of the present invention is subside active power and reactive power Output simulation figure.

Fig. 5 is line voltage surge voltage compensation analogous diagram of the present invention.

Fig. 6 is line voltage surge active power of the present invention and reactive power Output simulation figure.

Embodiment

The invention will be further described below in conjunction with embodiment and accompanying drawing, but should not limit protection scope of the present invention with this.

See also first Fig. 1, Fig. 1 is the structural representation of a kind of quality of power supply series compensator based on solar energy power generating of the present invention.As seen from the figure, a kind of quality of power supply series compensator based on solar energy power generating comprises: solar photovoltaic cell panel 2, DC/DC DC boosting unit 3, DC/AC(direct current become exchange) inversion unit 4, series transformer 5 consist of:

Described solar photovoltaic cell panel 2 is converted to electric energy with solar energy, two electric wires of its dc voltage output end link to each other with two electric wires of the direct-flow input end of described DC boosting unit 3, between two electric wires of the input of this DC boosting unit 3 and connect a direct current capacitor C _PV, two electric wires of the output of described DC boosting unit 3 link to each other with two electric wires of the direct-flow input end of described inversion unit 4, between two electric wires of the direct-flow input end of this inversion unit 4 and connect a direct current capacitor C _DC, two electric wires of the ac output end of described inversion unit 4 link to each other with the two ends of the primary coil of described series transformer 5, and the secondary coil of described series transformer 5 is serially connected in the power transmission line of electrical network, links to each other with load side with the common port PCC of electrical network respectively.

Fig. 2 is the voltage compensating principle schematic diagram, with

Be Reference(with reference to) drawn injecting voltage

PCC (common point) busbar voltage

Load voltage

Load current

Deng the relation between each vector, as seen from Figure 2, according to line voltage

Quality of power supply series compensator of the present invention is to the electrical network injecting voltage

Just can obtain the required voltage of loading

Fig. 3 is the analogous diagram of line voltage when subsideing (rapid drawdown), and when electric network fault caused that line voltage is subside, quality of power supply series compensator of the present invention injected line voltage

So that the amplitude of load voltage and phase angle are not affected by electric network fault, when solar energy was arranged, DC bus-bar voltage was with unaffected, and night, electrical network broke down when needing protection load, then needed to rely on dc-link capacitance C _DCEnergy storage, Fig. 4 be night during electric network fault in order to protect load, the waveform that quality of power supply series compensator DC bus-bar voltage of the present invention descends; Same, the analogous diagram when Fig. 5, Fig. 6 are line voltage surge (rising sharply), when electric network fault caused the line voltage surge, quality of power supply series compensator of the present invention injected line voltage So that the amplitude of load voltage and phase angle are not affected by electric network fault, thereby protected load.

Claims (1)

1. the quality of power supply series compensator based on wind-powered electricity generation is characterised in that to consist of to comprise: wind turbine (2), synchronous generator (3), rectification unit (4), three-phase H bridge inversion unit (5) and series transformer (6);

The annexation of above-mentioned parts is as follows:

Described wind turbine (2) is converted to mechanical energy with wind energy, and its output mechanical axis links to each other with the armature spindle of described synchronous generator (3), and the stator AC electricity output of this synchronous generator (3) links to each other with the input of described rectification unit (4); The output of this rectification unit (4) links to each other with the direct-flow input end of described three-phase H bridge inversion unit (5), two electric wires of the ac output end of this three-phase H bridge inversion unit (5) link to each other with the two ends of the primary coil of described series transformer (6), the secondary coil of described series transformer (6) is serially connected in the power transmission line of electrical network, links to each other with load side with the common port (PCC) of electrical network respectively.

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