CN105937477A - Wind power and photovoltaic microgrid water pumping and energy storing power generation system - Google Patents

Abstract

The invention discloses a wind power photovoltaic micro-grid pumped storage power generation system, which includes a micro-grid DC bus, an AC bus, a system controller, a photovoltaic power generation sub-system, a DC-DC controller, a capacitor switch group, a super capacitor group, and an energy storage system. Battery pack, bidirectional DC-DC controller, wind power generation subsystem, AC-DC controller, DC-AC controller, water pump switch set, water pump set, transfer switch set, reversible water turbine set, input switch set, generator set, water turbine group, step-up station and large power grid. Among them, both the wind power generation sub-system and the photovoltaic power generation sub-system can be controlled at maximum power to ensure maximum energy acquisition, regardless of system power balance and power quality, and control the number of input groups of supercapacitor banks to smooth the DC bus voltage of the microgrid. The bus voltage is stable. The power quality problems caused by wind power and photovoltaic can be ignored, the utilization rate of renewable energy power generation can be improved, and reliable, controllable and stable power can be provided to the large power grid.

Description

A wind power photovoltaic microgrid pumped storage power generation system

technical field

The invention belongs to the technical field of comprehensive utilization of new energy wind power generation and photovoltaic power generation microgrid, relates to the efficient and stable application of wind power and photovoltaic power generation, and specifically relates to a wind power photovoltaic microgrid pumped storage power generation system.

Background technique

With the continuous expansion of the capacity of wind turbines, the intermittent nature of wind power has caused most wind turbines to fail to be connected to the grid. The utilization efficiency of wind turbines is not high, and the photovoltaic power generation capacity is also increasing. Due to the characteristics of wind and wind power generation, its electric energy cannot be well connected to the large power grid. Many domestic units and individuals are studying how to efficiently and stably utilize wind and solar new energy. Teachers from Anhui Engineering University proposed an adaptive wind-solar complementary heating system. For example, some experts have proposed a method and device for integrated complementary power generation of water, wind, wind and biomass (Chinese patent application, application number: 201110201589.8). Utilize solar energy, biomass energy and other relatively concentrated renewable energy, and gather them around the hydropower station to form a multi-energy integrated complementary power generation system centered on hydropower, hydropower, wind and biomass, etc. A complementary control method for wind, water and gas power generation in regional power grids of small hydropower clusters (Chinese patent application, application number: 201510291179.5). The core of this patent is to balance the power of grid-connected wind power by adjusting the active power output of small hydropower groups. A hybrid wind-solar hybrid pumped storage system and its control method (Chinese patent application, application number: 201110300964.4), the core of the patent is: the traditional wind-solar hybrid system energy storage device - the battery pack is replaced by a pumped storage power generation system, and in The pumped storage unit uses a reversible pump-turbine to pump water or generate electricity, and uses the subsection integral method to monitor and control the energy of the upper pool of the pumped storage unit.

The pumped storage power generation in the hydroelectric power generation system pumps storage energy when the grid load is low, and generates power when the load is peak. Its power generation output is stable and does not cause impact on the large power grid. When the wind-solar micro-grid is connected to the large power grid, its power instability will cause a certain impact on the power grid. Combined with the advantages of pumped storage power generation, a wind-solar pumped-storage micro-grid is proposed. The core is that the electric energy of the wind-solar power generation system is not transmitted to the large grid, and all the electric energy is used for pumped storage. The pumping system is powered by ordinary AC pumps. It consists of a reversible pump-turbine unit, pipelines, a lower pool dam and an upper water dam; the water in the upper water dam is converted into electrical energy through a reversible pump-turbine unit and an ordinary hydro-generator unit, and the stable electrical energy is transmitted to the large power grid through boosting. The advantage of this invention is that it avoids the natural limitation of wind and wind, improves the utilization of wind and wind power generation systems, and can transmit reliable, stable and controllable electric energy to the large power grid by adjusting the pumped storage power generation system.

Contents of the invention

In view of the intermittent characteristics of wind power and the low efficiency of photovoltaic power generation caused by natural factors, the purpose of the present invention is to provide a wind power photovoltaic micro-grid pumped storage power generation system, which can ignore the power brought by wind power and photovoltaic power generation. Quality issues, maximize the efficiency of the use of renewable energy, improve power generation utilization and controllable output power, and provide reliable, controllable and stable power to the large power grid.

In order to realize above-mentioned task, the present invention takes following technical solution:

A wind power photovoltaic microgrid pumped storage power generation system, characterized in that the system includes a microgrid DC busbar, an AC busbar, a system controller, a photovoltaic power generation subsystem, a DC-DC controller, a capacitor switch group, and a supercapacitor group , energy storage battery pack, bidirectional DC-DC controller, wind power generation subsystem, AC-DC controller, DC-AC controller, water pump switch group, water pump unit, transfer switch group, reversible water turbine unit, input switch group, power generation Units, turbine units, booster stations and large power grids, of which:

The photovoltaic power generation subsystem and the wind power generation subsystem are respectively connected to the DC bus of the microgrid through the DC-DC controller and the AC-DC controller; the energy storage battery pack is also connected to the DC bus of the microgrid through the bidirectional DC-DC controller; The DC bus of the power grid is also connected to the super capacitor group through the capacitor switch group;

The DC bus of the microgrid is also connected to the DC-AC controller, and the DC-AC controller is connected to the water pump unit and the reversible water turbine unit respectively through the water pump switch group and the switch group;

The AC bus is connected to the large power grid through the step-up station, and the AC bus is connected to the generator set and the hydraulic turbine in series through the input switch group; the AC bus is also connected to the transfer switch group;

The system controller is respectively connected to the DC-DC controller, capacitor switch group, AC-DC controller, bidirectional DC-DC controller, DC-AC controller, input switch group, water pump switch group and transfer switch group.

The photovoltaic power generation subsystem according to the present invention is a photovoltaic array group.

The water pumps in the water pump unit are all three-phase AC water pumps.

In the wind power photovoltaic micro-grid pumped storage power generation system of the present invention, the wind power generation sub-system can perform maximum power tracking control to generate power after the wind speed reaches the requirement, and the photovoltaic power generation sub-system also performs maximum power tracking control, and the wind power generation sub-system is controlled by AC -DC controller, the photovoltaic power generation sub-system is connected to the DC bus of the microgrid through the DC-DC controller. By controlling the super capacitor group and the energy storage battery group, the water pump unit provides stable electric energy, and the water pump unit pumps water to the upper Water dams and Shangshui dams generate power through water wheels and generator sets under the control of the control system, and the power of water wheels and generator sets is boosted by a booster station and then incorporated into the large power grid. Its working process is:

After the wind speed reaches the start-up wind speed, the wind power generation sub-system starts and generates alternating current, and the AC-DC controller performs maximum power tracking control. After passing through the AC-DC controller, the electric energy flows to the DC bus of the microgrid, and the photovoltaic array group generates power through the DC-DC The converter is connected with the DC bus of the microgrid, and jointly outputs electric energy to the supercapacitor group, the energy storage battery group, and the water pump unit;

The supercapacitor bank is directly connected to the DC bus of the microgrid, and the voltage fluctuation of the DC bus of the microgrid is smoothed through the switching of the capacitor bank switch. The energy storage battery pack mainly provides backup energy storage and power supply for all secondary systems of the DC bus of the microgrid. The DC bus of the microgrid charges the energy storage battery pack through a bidirectional DC-DC converter. The energy storage battery provides electric energy to the DC bus of the microgrid through a bidirectional DC-DC converter. The DC bus of the microgrid is converted into AC to supply power to the water pump unit through DC-AC. The DC bus of the microgrid supplies power to the control system through the DC-AC controller, and at the same time supplies power to equipment such as lighting and communication. The reversible water turbine unit is connected to the DC-AC and the AC bus through a switch, and the water pump unit is connected to the DC-AC through a water pump switch. The system controller maintains communication with the DC-DC controller, capacitor switch group, AC-DC controller, bidirectional DC-DC controller, DC-AC controller, input switch group, water pump switch group and transfer switch group to exchange information, Obtain the information of wind power generation sub-system, photovoltaic power generation sub-system, and upper and lower water levels. After the system controller obtains these information, it will intelligently manage the power of the DC bus of the microgrid to give priority to the water pump unit for pumping. The reversible water turbine unit is converted into a water pump mode by switching the switch and put into pumped storage. Judging the water level information of the Shangshui dam, the priority is put into the hydro-generator unit for power generation. When the water level increases or the dispatch of the large power grid exceeds the quota of the hydro-generator unit group, the reversible hydro-turbine unit is gradually converted into power generation mode by switching the switch. The hydro-generator unit and reversible hydro-turbine unit are transmitted to the step-up station through the AC bus, and the step-up station is boosted to a certain voltage through the transformer and connected to the large power grid.

The supercapacitor bank of the DC bus of the microgrid performs dynamic instantaneous power balance, and the energy storage battery pack performs short-term power balance to ensure the voltage stability of the DC bus of the microgrid, so that the water pump unit, reversible water turbine unit, and hydroelectric generator unit can operate safely and securely. shutdown.

The start and stop of the generating set is controlled by the system controller, and its grid-connection control to the AC bus is controlled by its own control device to provide stable and controllable electric energy to the large power grid.

Compared with the prior art, the wind power photovoltaic microgrid pumped storage power generation system of the present invention has the following advantages:

Use renewable energy from the wind power generation sub-system and photovoltaic power generation sub-system with maximum efficiency to reduce the impact of intermittent characteristics on the power quality of the power grid. Provide controllable, reliable and stable power.

Both the wind power generation sub-system and the photovoltaic power generation sub-system in the system can be controlled at maximum power to ensure maximum energy acquisition, regardless of system power balance and power quality issues. Therefore, the operation will not be restricted due to grid power quality problems. The system adopts micro-grid DC bus structure, and the power exchange technology with each unit is easy to realize.

A supercapacitor bank is installed on the DC bus of the microgrid, and the number of its input groups is controlled to smooth the DC bus voltage of the microgrid and keep the bus voltage stable.

The reversible water turbine unit, water pump unit, generator set, and all the electric energy of the DC bus of the microgrid are first supplied to the water pump unit to pump water from the lower dam to the upper water dam. When the electric energy is excessive, start and switch the reversible water turbine unit to pump mode for pumped storage; The generator set generates power according to the control instructions of the system controller. When the water level is too high or the required power exceeds the output of the unit, the reversible turbine unit is switched to the power generation mode to supply power to the large power grid.

The system controller maintains communication with the DC-DC controller, capacitor switch group, AC-DC controller, bidirectional DC-DC controller, DC-AC controller, input switch group, water pump switch group and transfer switch group for information exchange and Control can keep the system running stably. At the same time, the system controller can perform intelligent control based on information such as water level, wind and electricity, and grid-side demand. At the same time, it can accept external dispatch instructions to meet the overall planning and dispatch of the regional power grid.

Description of drawings

Fig. 1 is a schematic structural diagram of the wind power photovoltaic microgrid pumped storage power generation system of the present invention.

The marks in the figure respectively represent: 1. Microgrid DC bus, 2. AC bus, 3. System controller, 4. Photovoltaic power generation sub-system, 5. DC-DC controller, 6. Capacitor switch group, 23. Supercapacitor Group, 7. Energy storage battery group, 8. Bidirectional DC-DC controller, 9. Wind power generation subsystem, 10. AC-DC controller, 11. DC-AC controller, 12. Water pump switch group, 13. Water pump Unit, 14, switch group, 15, reversible water turbine unit, 16, launching dam, 17, input switch group, 18, generator set, 19, ordinary water turbine unit, 20, sheungshui dam, 21, booster station, 22, big grid.

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

detailed description

The key point of the design idea of the present invention is that the electric energy of wind power and photovoltaic is used for pumped storage. The pumped storage system contains three types of units: ordinary water pump units, reversible water turbine units and ordinary hydroelectric generator units. The units need intelligent system controllers. Interpret all information of the system to start and stop.

Referring to Figure 1, this embodiment provides a wind power photovoltaic microgrid pumped storage power generation system, the system includes microgrid DC bus 1, AC bus 2, system controller 3, photovoltaic power generation subsystem 4, DC -DC controller 5, capacitor switch group 6, super capacitor group 23, energy storage battery group 7, bidirectional DC-DC controller 8, wind power generation subsystem 9, AC-DC controller 10, DC-AC controller 11, Water pump switch group 12, water pump unit 13, transfer switch group 14, reversible water turbine unit 15, input switch group 17, generator set 18, ordinary water turbine unit 19, booster station 21 and large power grid 22, of which:

The photovoltaic power generation subsystem 4 and the wind power generation subsystem 9 are connected to the microgrid DC bus 1 through the DC-DC controller 5 and the AC-DC controller 10 respectively; the energy storage battery pack 7 is also connected to the On the DC bus 1 of the microgrid; the DC bus 1 of the microgrid is also connected to the supercapacitor group 23 through the capacitor switch group 6;

The DC bus 1 of the microgrid is also connected to the DC-AC controller 11, and the DC-AC controller 11 is respectively connected to the water pump unit 13 and the reversible water turbine unit 15 through the water pump switch group 12 and the switch group 14; the water pump unit 13 and the reversible water turbine unit 15 are respectively Access the water of the launching dam 16 through pipelines;

The AC bus 2 is connected to the large power grid 22 through the step-up station 21, and the AC bus 2 is connected in series with the generator set 18 and the ordinary water turbine unit 19 through the switch group 17; the AC bus 2 is also connected with the switch group 14;

System controller 3 is respectively connected to DC-DC controller 5, capacitor switch group 6, AC-DC controller 10, bidirectional DC-DC controller 8, DC-AC controller 11, input switch group 17, water pump switch group 12 and Toggle switch group 14.

In this embodiment, the photovoltaic power generation subsystem 4 selects a photovoltaic array group.

The water pumps in the water pump unit 13 all adopt three-phase AC water pumps.

Capacitor switch group 6, supercapacitor group 23, energy storage battery group 7, water pump switch group 12, water pump unit 13, transfer switch group 14, reversible water turbine unit 15, input switch group 17, generator unit 18 described in this embodiment , the ordinary water turbine unit 19, wherein the "group" means to contain several identical parts, for example, the capacitor switch group 6 includes several capacitor switches, and the ordinary water turbine unit 19 includes several water turbines, etc., the figure uses ". .." mark.

After the wind speed reaches the starting wind speed, the wind power generation subsystem 9 starts and generates alternating current, and is connected to the DC bus 1 of the microgrid through the AC-DC controller 10, and the photovoltaic power generation subsystem 4 is connected to the DC bus 1 of the microgrid through the DC-DC controller 5 connected, and jointly output electric energy to the supercapacitor group 23, the energy storage battery group 7, the water pump unit 13 and the reversible water turbine unit 15.

The energy storage battery group 7 is connected to the DC bus of the microgrid through the DC-DC controller. When the output of the wind power generation subsystem and the photovoltaic power generation subsystem is almost zero, it will provide electric energy to the DC bus of the microgrid for a short time to ensure that the water pump unit and reversible water turbine group, hydroelectric generating set shut down safely.

The supercapacitor bank 23 is connected to the DC bus 1 of the microgrid through a capacitor bank switch, which can balance the instantaneous voltage fluctuation of the DC bus 1 of the microgrid.

The DC bus 1 of the microgrid charges the battery pack through the controllable bidirectional DC-DC converter 8, and at the same time, when the voltage drop of the DC bus 1 is serious, the energy storage battery pack 7 discharges the DC bus 1 of the microgrid through the bidirectional DC-DC controller 8 , keep the voltage within the allowable value range.

The water pump units 13 all use three-phase AC water pumps, and the DC bus 1 of the microgrid is converted into alternating current through the controllable DC-AC controller 11 to supply power to the water pump units 13 , pumping water from the lower water dam 16 to the upper water dam 20 .

The water pump unit 13 is intelligently judged by the system controller, and the number of input water pumps is controlled by the water pump switch group 12:

When the power supply of the DC bus 1 of the microgrid exceeds the load of the water pump unit 13, the DC-AC controller 11 is connected to the reversible water turbine unit 15 through the switch group 14, and the system controller 3 controls the switch group 14 to switch the reversible water turbine unit 15 Among them, one or several units are pumping mode, and water is pumped from the lower water dam 16 to the upper water dam 20 .

The reversible hydraulic turbine unit 5 is connected to the AC bus 2 of the pumped storage power generation sub-system through the switching switch group 14, the generator set 18 and the ordinary hydraulic turbine unit 19 are connected to the AC bus 2 through the input switch group 17, and the AC bus 2 of the pumped storage power generation sub-system passes through The booster station 21 supplies power to the large power grid 23 .

System controller 3 collects DC-DC controller 5, capacitor switch group 6, AC-DC controller 10, bidirectional DC-DC controller 8, DC-AC controller 11, input switch group 17, water pump switch group 12 and switching The switch group 14, as well as the microgrid DC bus, AC bus, water level information of the large power grid, grid information, grid dispatching instructions, etc., ensure that the input voltage of the water pump unit is stable within the allowable value range, control and input the switch group 17, and input the ordinary water turbine unit 19 to carry out To generate power, the generator set 18 is sent to the booster station 21 through the AC bus 2. When the water level is too high or the demand on the grid side is too large, one or several reversible water turbine sets 15 are switched to the power generation mode by controlling the switch group 14. The switch group 14 is connected to the grid on the AC bus 2. When the water level of the upstream dam 20 is too low, the system controller 3 will gradually cut it off in the order from the reversible hydraulic turbine unit 15 to the hydroelectric generator unit 19. When the water level of the downstream dam 16 is too low , the system controller 3 is gradually cut off in the order from the reversible water turbine unit 15 to the water pump unit 13 .

Claims (3)

1. a wind-powered electricity generation photovoltaic micro pumped storage system, it is characterised in that this system includes There is micro-capacitance sensor dc bus (1), ac bus (2), system controller (3), photovoltaic generation System (4), DC-DC controller (5), capacitance switch group (6), super capacitor group (23), Energy storage battery group (7), bi-directional DC-DC controller (8), wind-power electricity generation subsystem (9), AC-DC Controller (10), DC-AC controller (11), pump switch group (12), water pump assembly (13), Switching switches set (14), reversible water turbine set (15), put into switches set (17), generating set (18), Common water turbine set (19), booster stations (21) and bulk power grid (22), wherein:

Photovoltaic generation subsystem (4) and wind-power electricity generation subsystem (9) are respectively by DC-DC controller (5) It is connected with micro-capacitance sensor dc bus (1) with AC-DC controller (10)；Energy storage battery group (7) is led to Cross bi-directional DC-DC controller (8) to be also connected on micro-capacitance sensor dc bus (1)；Micro-capacitance sensor direct current is female Line (1) connects super capacitor group (23) also by capacitance switch group (6)；

Micro-capacitance sensor dc bus (1) is also connected with DC-AC controller (11), DC-AC controller (11) Water pump assembly (13) and reversible is connected respectively by pump switch group (12) and switching switches set (14) Water turbine set (15)；Water pump assembly (13) and reversible water turbine set (15) are accessed by pipeline respectively In lower water dykes and dams water；

Ac bus (2) connects bulk power grid (22) by booster stations (21), and ac bus (2) leads to Cross input switches set (17) and be connected in series generating set (18) and common water turbine set (19)；Exchange Bus (2) is also connected with switching switches set (14)；

System controller (3) connects DC-DC controller (5), capacitance switch group (6), AC-DC respectively Controller (10), bi-directional DC-DC controller (8), DC-AC controller (11), input switch Group (17), pump switch group (12) and switching switches set (14).

2. wind-powered electricity generation photovoltaic micro pumped storage system as claimed in claim 1, its feature exists In, described photovoltaic generation subsystem (4) is photovoltaic array group.

3. wind-powered electricity generation photovoltaic micro pumped storage system as claimed in claim 1, its feature exists In, the described water pump in water pump assembly all uses three-phase alternating current water pump.