阅读说明：本技术 中高压大功率光伏水泵控制系统及方法 (Medium-high voltage high-power photovoltaic water pump control system and method ) 是由 李勇 刘云 庄勇 李嘉欣 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种中高压大功率光伏水泵控制系统及方法,属于光伏水泵控制技术领域；包括光伏发电组件和光伏水泵,其还包括高压变频功率单元和DSP控制系统,所述高压变频功率单元与所述光伏发电组件电连接,所述高压变频功率单元还与DSP控制系统连接,所述DSP控制系统包括SVPWM模块和MPPT模块,多个所述高压变频功率单元串联成一组,总共设置三组且构成Y型接法以给光伏水泵供电；本发明利用较低的光伏电压供电实现较高的电压及功率控制输出,极大的降低了对各设备单元的电气绝缘要求,系统安全性也得到较大的提升,更能满足中高压大功率光伏水泵控制使用。(The invention discloses a medium-high voltage high-power photovoltaic water pump control system and a method, belonging to the technical field of photovoltaic water pump control; the photovoltaic power generation system comprises a photovoltaic power generation assembly, a photovoltaic water pump, a high-voltage variable-frequency power unit and a DSP control system, wherein the high-voltage variable-frequency power unit is electrically connected with the photovoltaic power generation assembly and is also connected with the DSP control system, the DSP control system comprises an SVPWM module and an MPPT module, a plurality of high-voltage variable-frequency power units are connected in series to form a group, three groups are arranged in total, and a Y-shaped connection method is formed to supply power to the photovoltaic water pump; the invention utilizes lower photovoltaic voltage to supply power to realize higher voltage and power control output, greatly reduces the electrical insulation requirement on each equipment unit, greatly improves the system safety, and can better meet the control and use of medium-high voltage high-power photovoltaic water pumps.)

1. High-power photovoltaic water pump control system of well high pressure, including photovoltaic power generation subassembly (1) and photovoltaic water pump, its characterized in that: the photovoltaic power generation system is characterized by further comprising a high-voltage frequency conversion power unit and a DSP control system, wherein the high-voltage frequency conversion power unit is electrically connected with the photovoltaic power generation assembly (1), the high-voltage frequency conversion power unit is further connected with the DSP control system, the DSP control system comprises an SVPWM module and an MPPT module, the high-voltage frequency conversion power units are connected in series to form a group, three groups are arranged in total, and a Y-shaped connection method is formed to supply power to the photovoltaic water pump.

2. The medium-high voltage high power photovoltaic water pump control system according to claim 1, characterized in that: the rated photovoltaic direct-current power supply voltage of the photovoltaic power generation assembly (1) is 1100V, the high-voltage frequency conversion power units are modulated by an SVPWM module of a DSP control system to generate rated 690V alternating-current voltage at the alternating-current output ends of the high-voltage frequency conversion power units, and the eight high-voltage frequency conversion power units are connected in series to form a group.

3. The medium-high voltage high power photovoltaic water pump control system according to claim 2, characterized in that: the photovoltaic power generation assembly (1) comprises a solar cell panel, branch header boxes and a main header box, wherein the input end of the main header box is connected with a plurality of branch header boxes, each branch header box is connected with one solar cell panel, and the output end of the main header box is connected with a high-voltage variable-frequency power unit.

4. The control method of the medium-high pressure high-power photovoltaic water pump adopts the medium-high pressure high-power photovoltaic water pump control system as claimed in any one of claims 1 to 3, and is characterized in that: 24 high-voltage frequency conversion power units are arranged and are respectively modulated by an SVPWM module and an MPPT module of a DSP control system, the input end of each high-voltage frequency conversion power unit is respectively provided with 1100V rated direct current by a photovoltaic power generation assembly (1), the rated output voltage of each high-voltage frequency conversion power unit is modulated into 690V alternating voltage by the DSP control system, 8 high-voltage frequency conversion power units are connected in series to form a phase, the output of the phase is 5520V, the three phases form a Y-shaped connection method, and the voltage of the three phase lines generates 10KV level voltage to supply power to a photovoltaic water pump.

Technical Field

The invention discloses a medium-high voltage high-power photovoltaic water pump control system and method, and belongs to the technical field of photovoltaic water pump control.

Background

The solar photovoltaic water pump system is a novel water pump system, solar energy is converted into electric energy by using a solar cell module, and a matched power electronic device is used for driving a water pump to pump water; the photovoltaic water pump can work in places with sunlight without depending on a power grid. The solar photovoltaic water pump system mainly comprises a solar power generation system (a solar battery array), a photovoltaic pumping inversion control system (a photovoltaic pumping inverter) and a water lifting system (a photovoltaic water pump). The system principle is as follows: the solar cell array is formed by connecting a plurality of solar cell modules in series and parallel, absorbs sunlight radiation energy, converts the sunlight radiation energy into electric energy and provides a power supply for the whole system. The photovoltaic pumping inversion control system controls and regulates the operation of the system, converts direct current generated by the solar cell array into alternating current to drive the photovoltaic water pump, and regulates output frequency and voltage in real time according to the change of sunlight intensity, so that maximum power point tracking is realized, and solar energy is utilized to the maximum extent.

The solar photovoltaic water pump system runs fully automatically without manual guard and only a small amount of daily manual maintenance; an energy storage device such as a storage battery is omitted, stored water is used for replacing electric power storage, the water pump is directly driven to pump water, the reliability is high, and meanwhile the construction and maintenance cost of the system is greatly reduced. All equipment all works all weather, possesses high efficiency low light work function, still can exert higher work efficiency in cloudy weather, ensures the water use of cloudy and cloudy day. Advanced MPPT control technology and novel frequency conversion contravariant technology, the solar module generated energy change that real-time supervision sunshine intensity changes and arouses adjusts water pump operating frequency and rotational speed, makes output close to the maximum power of solar array. The full digital control has full automatic operation and perfect protection function. The solar photovoltaic water pump system can be widely applied to the fields of agricultural irrigation, desert control, grassland animal husbandry, urban waterscape, domestic water, tree planting and afforestation and the like.

The photovoltaic water pump system design configuration needs according to the requirement of the lift and the flow of project place, the length of water delivery distance and local sunshine condition, carries out the optimal design: the method comprises the steps of determining the optimal average daily operation time and the water pump speed regulation range, selecting the optimal lift and rated power of the water pump, determining the maximum power, the optimal working voltage and the wiring mode of the solar cell module and the like. For a common photovoltaic pump station, the voltage of a water pump motor is usually 380V or 690V of three-phase alternating current for power supply. However, for a photovoltaic pump station with a motor power of hundreds or even more than kilowatt, the output voltage level of the alternating current side is usually designed to be 10KV, the design power of each stage of single pump is 300 KW-850 KW or even higher, the single pump has higher power, the voltage insulation level requirement is high, the safety is lower, and the common photovoltaic pump station design can not meet the requirement.

Disclosure of Invention

Technical problem to be solved

The invention aims to solve the technical problem that the existing medium-high pressure high-power photovoltaic water pump has high power and the design of a common photovoltaic pump station can not meet the requirement.

(II) technical scheme

In order to solve the technical problems, the invention provides a medium-high voltage high-power photovoltaic water pump control system which comprises a photovoltaic power generation assembly, a photovoltaic water pump, a high-voltage frequency conversion power unit and a DSP control system, wherein the high-voltage frequency conversion power unit is electrically connected with the photovoltaic power generation assembly, the high-voltage frequency conversion power unit is also connected with the DSP control system, the DSP control system comprises an SVPWM module and an MPPT module, a plurality of high-voltage frequency conversion power units are connected in series into a group, and three groups are arranged to form a Y-shaped connection method for supplying power to the photovoltaic water pump.

Furthermore, the rated photovoltaic direct-current power supply voltage of the photovoltaic power generation assembly is 1100V, the high-voltage frequency conversion power units are modulated by an SVPWM module of the DSP control system to generate rated 690V alternating-current voltage at the alternating-current output ends of the high-voltage frequency conversion power units, and the eight high-voltage frequency conversion power units are connected in series to form a group.

Furthermore, the photovoltaic power generation assembly comprises a solar cell panel, branch combiner boxes and a main combiner box, wherein the input end of the main combiner box is connected with a plurality of branch combiner boxes, each branch combiner box is connected with one solar cell panel, and the output end of the main combiner box is connected with a high-voltage variable-frequency power unit.

The invention also provides a medium-high voltage high-power photovoltaic water pump control method, which adopts the medium-high voltage high-power photovoltaic water pump control system, 24 high-voltage frequency conversion power units are arranged and are respectively modulated by the SVPWM module and the MPPT module of the DSP control system, the input end of each high-voltage frequency conversion power unit is respectively provided with 1100V rated direct current by a photovoltaic power generation assembly, the rated output voltage of each high-voltage frequency conversion power unit is modulated into 690V alternating current voltage by the DSP control system, each 8 high-voltage frequency conversion power units are connected in series to form one phase, the output of one phase is 5520V, the three phases form a Y-shaped connection method, and the voltage of 10KV grade is generated by the voltage of three phase lines to supply power to the photovoltaic water pump.

(III) advantageous effects

The technical scheme of the invention has the following advantages:

aiming at the medium-high voltage high-power photovoltaic water pump, the invention particularly designs and selects a high-voltage frequency conversion power unit (frequency converter), adopts a topological structure design of 'unit series connection multi-level', controls the frequency and the phase of the output voltage of each high-voltage frequency conversion power unit by a DSP control system, and the output voltage of each phase is formed by modulating and overlapping a plurality of high-voltage frequency conversion power units through SVPWM (space vector pulse width modulation) waveforms, thereby not only meeting the output of high-voltage grades, but also reducing the voltage insulation grade requirement on each high-voltage frequency conversion power unit, having higher safety, and overcoming the problems that the existing medium-high voltage high-power photovoltaic water pump has larger power and the common photovoltaic pump station design can not meet the requirement. The invention also has the following advantages:

the structure and the electrical performance of each high-voltage variable-frequency power unit are completely consistent, and the high-voltage variable-frequency power units can be interchanged, are convenient to overhaul and replace, and realize modular design. The high-voltage variable-frequency power unit adopts an SVPWM (space vector pulse width modulation) mode to control the on and off of output and output a single-phase pulse width modulation waveform, so that the high-voltage variable-frequency power unit has extremely high safety and good electromagnetic compatibility;

and secondly, each high-voltage frequency conversion power unit is controlled by a DSP control system, so that all the high-voltage frequency conversion power units are coordinated to work and control, and various protection functions of the motor and the frequency converter are realized. The DSP control system and the high-voltage frequency conversion power unit are communicated by high-speed optical fibers, so that complete electrical isolation between the DSP control system and the high-voltage power supply is ensured, and the system has extremely high safety and anti-interference capability.

And thirdly, the photovoltaic power generation assembly supplies power to 1100V direct current, all the high-voltage frequency conversion power units simultaneously supply power, the photovoltaic direct current voltage also changes along with the change of the intensity of sunlight, the DSP control system controls the output of each high-voltage frequency conversion power unit through the MPPT maximum power tracking module according to the change of the intensity of the sunlight, high-voltage alternating current with the frequency of 0-50 HZ and the voltage of 0-10 KV is generated at the total output end to drive the photovoltaic water pump motor to operate, the high-power photovoltaic water pump with the voltage of 10KV changes the operating frequency along with the change of the intensity of the sunlight, and the photovoltaic water pump is driven to lift water by the maximum power obtained by photovoltaic power generation.

The design has the greatest advantage that the higher voltage and power control output is realized by the lower photovoltaic voltage power supply, the electrical insulation requirement on each equipment unit is greatly reduced, and the system safety is also greatly improved.

In addition to the technical problems addressed by the present invention, the technical features constituting the technical solutions and the advantages brought by the technical features of the technical solutions described above, other technical features of the present invention and the advantages brought by the technical features of the technical solutions will be further explained with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is an electrical block diagram of the present invention.

Fig. 2 is a schematic diagram of 8 high-voltage frequency-conversion power units connected in series to generate a phase 5520V high voltage (the combiner box is not shown).

Fig. 3 is a schematic diagram of voltage superposition of 10 KV.

Fig. 4 is a schematic diagram of a superposition principle of multi-level output voltages of high-voltage frequency conversion power units connected in series.

In the figure: 1-photovoltaic power generation assembly.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" should be construed broadly and include, for example, fixed connections, detachable connections, or integral connections; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, in the description of the invention, unless otherwise specified, the terms "plurality", and "groups" mean two or more, and the terms "a plurality", "several", and "several groups" mean one or more. In the description of the present invention, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used for indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the use of the terms first, second and third are used for descriptive purposes only and are not intended to indicate or imply relative importance.

As shown in fig. 1-4: high-power photovoltaic water pump control system of well high pressure, including photovoltaic power generation subassembly 1 and photovoltaic water pump, it still includes high-pressure frequency conversion power unit and DSP control system, high-pressure frequency conversion power unit with photovoltaic power generation subassembly 1 electricity is connected, high-pressure frequency conversion power unit still is connected with DSP control system, DSP control system includes SVPWM module and MPPT module, and is a plurality of high-pressure frequency conversion power unit establishes ties into a set ofly, sets up three groups altogether and constitutes Y type and connects the method in order to supply power for the photovoltaic water pump. The rated photovoltaic direct-current power supply voltage of the photovoltaic power generation assembly 1 is 1100V, the high-voltage frequency conversion power units are modulated by an SVPWM module of a DSP control system to generate rated 690V alternating-current voltage at the alternating-current output ends of the high-voltage frequency conversion power units, and the eight high-voltage frequency conversion power units are connected in series to form a group. The photovoltaic power generation assembly 1 comprises a solar cell panel, branch combiner boxes and a main combiner box, wherein the input end of the main combiner box is connected with a plurality of branch combiner boxes, each branch combiner box is connected with one solar cell panel, and the output end of the main combiner box is connected with a high-voltage variable-frequency power unit.

The control method of the medium-high voltage high-power photovoltaic water pump adopts the medium-high voltage high-power photovoltaic water pump control system, 24 high-voltage frequency conversion power units are arranged and are respectively modulated by an SVPWM module and an MPPT module of a DSP control system, the input end of each high-voltage frequency conversion power unit is respectively provided with 1100V rated direct current by a photovoltaic power generation assembly 1, the rated output voltage of each high-voltage frequency conversion power unit is modulated into 690V alternating current voltage by the DSP control system, each 8 high-voltage frequency conversion power units are connected in series to form one phase, the output of one phase is 5520V, the three phases form a Y-shaped connection method, and the three-phase line voltage generates 10 KV-level voltage to supply power to the photovoltaic water pump.

And (4) DSP: a digital signal processor, wherein an SVPWM (space vector pulse width modulation) module is an output voltage control module; the MPPT module is a maximum power point tracking module of the photovoltaic power generation assembly 1 and is used for adjusting the maximum power point working voltage of the photovoltaic power generation assembly 1.

While the present invention has been described in detail with reference to the specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.