CN206807027U - Solar power generation emergency power supply system - Google Patents

Abstract

The utility model discloses an emergency power supply system for solar power generation, which comprises an independent photovoltaic power generation system and a grid-connected/off-grid photovoltaic power generation system connected in parallel therewith. A DC/DC converter and a storage battery, a photovoltaic controller for preventing overcharging and over-discharging of the storage battery is arranged between the DC/DC converter and the storage battery; the grid-connected/off-grid photovoltaic power generation system includes a second solar cell assembly And a grid-connected inverter for grid-connected/off-grid switching, the grid-connected inverter includes a DC/DC control module and a DC/AC control module; the utility model is based on a reliable, stable, low-carbon and environmentally friendly solar power generation principle , combine grid-connected power generation with off-grid power generation, realize automatic control and intelligent adjustment two power generation working modes according to the specific conditions of the power grid, ensure the power generation effect in emergency conditions, and also obtain power through grid-connected power generation in daily life Better economic benefits.

Description

Solar power emergency power supply system

technical field

The utility model relates to a new energy power generation system, in particular to an emergency power supply system for solar power generation.

Background technique

In today's society where natural disasters occur frequently, problems such as power supply interruptions caused by sudden natural disasters to the power system have brought great resistance to rescue and disaster relief. After the disaster, when the power system is completely interrupted, the secondary disasters caused by the failure of the communication system, the inability of the hospital to treat the wounded, and the panic of the affected people cannot be ignored. Harmful. In the context of the country's vigorous promotion of new energy, the traditional power supply method is no longer respected due to its drawbacks and flaws.

Utility model content

Purpose of the utility model: Aiming at the problems existing in the above-mentioned prior art, the purpose of the utility model is to provide an emergency power supply system for solar power generation that can perform grid-connected work under normal conditions and off-grid power supply under emergency conditions.

Technical solution: A solar power generation emergency power supply system described in the utility model includes an independent photovoltaic power generation system and a grid-connected/off-grid photovoltaic power generation system connected in parallel therewith. The independent photovoltaic power generation system includes a first solar cell module, a The step-up DC/DC converter and the storage battery are provided with a photovoltaic controller for preventing overcharging and over-discharging of the storage battery between the DC/DC converter and the storage battery; the grid-connected/off-grid photovoltaic power generation system includes the first Two solar battery components and a grid-connected inverter for grid-connected/off-grid switching, the grid-connected inverter includes a DC/DC control module and a DC/AC control module, and the DC/AC control module is connected to the DC/AC The output terminal of the DC control module. The grid-connected inverter preferably uses ATmega64 as the main control chip.

The photovoltaic controller includes a detection control circuit for providing a pulse trigger signal, a fuse FU connected in series with the battery, an anti-reverse connection diode VD connected in parallel with the battery, and a first transistor V1 connected in parallel at the output end of the first solar cell module And the second transistor V2 connected in series in the circuit. Preferably, the photovoltaic controller also includes a light control switch and a time control switch. In order to facilitate monitoring of the working status of the system, the photovoltaic controller can also be connected with an external display screen.

The DC/DC control module includes a PWM generation circuit and a high-frequency transformer TR. An IR2110s driver chip is connected in series at both ends of the PWM generation circuit. The IR2110s driver chip is connected to four IGBT thyristors. The IGBT transistor and the high-frequency transformer Connected, the high-frequency transformer provides pulse pulse signals to the IGBT transistors. Preferably, the PWM generating circuit adopts UC3875 chip.

The DC/AC control module includes a full-bridge inverter circuit, a filter circuit, a grid-connected/off-grid switching protection circuit, a current feedback control circuit, and a voltage feedback control circuit; the full-bridge inverter circuit is composed of four IGBT transistors; When the emergency power supply system is in the grid-connected working mode, the grid-connected/off-grid switching protection circuit is connected to the current feedback control circuit, and when the off-grid independent working mode is performed, the grid-connected/off-grid switching protection circuit is connected to the voltage feedback control circuit Control circuit.

Beneficial effects: Compared with the prior art, the utility model has the advantages that: the system development and utilization of new energy in the utility model can reduce the use of fossil fuels, reduce the emission of greenhouse gases, and its environmental friendliness is self-evident; secondly , can realize switching between grid-connected and off-grid modes, grid-connected power generation can bring good economic benefits in non-emergency situations, thereby reducing installation and use costs, and is of great significance for emergency rescue and disaster relief and protection of people's property safety in emergency situations; As an emergency power generation system, the system is equipped with a battery protection circuit and a solar battery protection circuit to make the system run stably and efficiently.

Description of drawings

Fig. 1 is the structural representation of the utility model 5Kw solar emergency power supply system;

Fig. 2 is the control schematic diagram of the storage battery of the utility model to prevent overcharging and over-discharging;

Fig. 3 is the design diagram of the DC/DC control module of the inverter part of the utility model;

Fig. 4 is a design diagram of the DC/AC control module of the inverter part of the utility model.

detailed description

The technical solution of the utility model will be described in further detail below in conjunction with the embodiments and accompanying drawings.

As shown in Figure 1, an emergency power supply system for solar power generation, the system includes an independent photovoltaic power generation system 1 and a grid-connected/off-grid photovoltaic power generation system 2 connected in parallel therewith, and the independent photovoltaic power generation system 1 includes a first solar cell A component 101, a DC/DC converter 102 for step-up and a storage battery 103, a photovoltaic controller 104 for preventing overcharging and over-discharging of the storage battery is arranged between the DC/DC converter 102 and the storage battery 103; The on-grid/off-grid photovoltaic power generation system 2 includes a second solar cell module 201 and a grid-connected inverter 202 for on-grid/off-grid switching, and the grid-connected inverter 202 includes a DC/DC control module and a DC/AC Control module; this utility model is based on the principle of switching photovoltaic power generation system, and integrates two modes of off-grid and grid-connected, forming the function of automatically operating grid-connected power generation and switching off-grid power supply. In this embodiment, the first solar cell module 101 is a 250w solar cell module, and the second solar cell module 201 is a 5kw solar cell module; In the case of natural disasters, the 250W solar cell module works normally at this time to supply power to the battery; the 5KW solar cell module generates electricity and connects to the grid, resulting in good economic benefits. When the off-grid power generation mode is used, it is usually caused by sudden natural disasters in the local area, resulting in insufficient battery power and power outages and power cuts in the grid. At this time, it can operate independently to supply power to the battery. In the second mode, the system is As an emergency communication power supply, medical equipment, gas station, shelter indication and lighting and other important places or emergency load power supply system.

The function of the photovoltaic controller 104 is to control the working state of the whole system. Its functions mainly include battery overcharge protection, battery overdischarge protection, system short-circuit electronic protection, system polarity reverse connection protection, and nighttime charge protection. In places where the temperature difference is large, the controller also has the function of temperature compensation. In addition, the controller also has working modes such as light control switch and time control switch, as well as display functions of various working states such as charging state and battery power. As shown in Figure 2, it is a schematic diagram of photovoltaic control for battery anti-overcharge and overdischarge; based on the advantages of transistor IGBT with high input impedance of MOSFET and low conduction voltage drop of GTR, the photovoltaic control circuit includes a detection control circuit, A fuse FU, a diode VD, a first transistor V1 and a second transistor V2 are connected in series in the circuit. Wherein, the first transistor V1 is connected in parallel with the output end of the solar cell. When the battery voltage exceeds the set full-charge disconnection voltage of the battery, the first transistor V1 short-circuits the battery and no longer charges the battery, thereby ensuring that the battery will not be overcharged and playing the role of "overcharge protection" for the battery. The first transistor V1 also has the function of "anti-reverse charging". Only when the output voltage of the solar cell module is greater than the battery voltage, V1 can be turned on, otherwise V1 is cut off, so as to ensure that there will be no charging of the battery to the solar battery at night and in rainy weather. Reverse charging plays the role of "anti-reverse charging" for the battery. The pulse trigger signal is provided by the detection control circuit, and the second transistor V2 is a battery discharge switch. When the load is overloaded or short-circuited, the line current is much greater than the rated current, and V2 is blocked to play "output overload protection" and "output short-circuit protection". effect. At the same time, when the battery voltage is much lower than the "over-discharge voltage", V2 will also be blocked to perform "over-discharge protection". VD2 is an "anti-reverse connection diode". When the polarity of the battery is reversed, VD2 conducts, causing the battery to short-circuit discharge through VD2, generating a large current and quickly blowing the fuse FU, and the circuit acts as an "anti-battery reverse connection protection" "effect.

Devices such as V1, V2, VD2 and fuse FU together form the battery protection circuit, which has the characteristics of simple circuit, low price, small charging circuit loss and high control efficiency.

The grid-connected inverter 202 is composed of charge and discharge control, power regulation, AC inverter, grid-connected protection switching, etc. The AC power output by the inverter is used by the load, and the excess electric energy can be fed back to the public through power transformers and other equipment. grid or to charge the battery. It is mainly composed of two parts, the first part is the DC/DC control module, and the second part is the DC/AC control module. The basic principle of the inverter is mainly to convert low-voltage direct current into high-frequency low-voltage alternating current through high-frequency DC/DC conversion technology, then step up the voltage through a high-frequency transformer, and then rectify it into a high-voltage direct current of about 380V through a high-frequency rectification and filtering circuit. Finally, the 220V power frequency alternating current is obtained for the load through the power frequency inverter circuit. The structure of this circuit has the advantages of small no-load loss, high inverter efficiency, stable operation, and low distortion.

In this embodiment, the grid-connected inverter adopts the high-performance, low-power 8-bit microprocessor ATmega64 produced by ATMEL Company as the main control chip, which has an advanced RISC structure and 53 programmable I/O lines , 64-pin TQFP and 64-pin MLF packages, the working voltage is 2.7-5.5V, and the performance is up to 16MIPS when working at 16MHz.

Figure 3 shows the schematic diagram of the structure of the DC/DC control module. Using the UC3875 chip, the chip can generate four PWM square waves. By receiving the feedback signal output by the voltage sensor, it is compared with the internal 2.5V standard signal to adjust The phase difference of the four-way PWM wave, and then drive the four IGBT transistors in the two driver chips IR2110s, so as to achieve the purpose of controlling the DC/DC module and closed-loop control. This circuit includes the function of input over-current protection. When the input is over-current, the protection signal generated by the system is compared with the over-current threshold inside the UC3875 chip after signal conditioning, so that the chip UC3875 locks and trips; the main control chip Mega64 passes SYN and SS The pin provides 128KHZ synchronous signal and start and stop signal for UC3875.

The structural schematic diagram of the DC/AC control module is shown in Figure 4. The control circuit integrates grid-connection and off-grid in one circuit system. The DC high voltage output by the DC/DC module converter is used as the inverter input, passes through the full-bridge inverter circuit composed of four IGBT transistors, and then passes through the output filter circuit to generate the required sinusoidal 220V/50Hz AC. The inverter circuit has two working modes, one is the off-grid independent mode, which supplies power to local loads and adopts voltage feedback control. The other is the grid-connected mode, where the invertered electric energy is sent to the grid, and current feedback control is adopted.

The utility model combines the advantages of grid-connected power generation and off-grid power generation through the application of solar photovoltaic power generation, so that the emergency power generation effect of the system is greatly improved. In addition, the design of the controller circuit plays an important role in balancing the energy of the photovoltaic system, protecting the storage battery and solar cells, and the normal operation of the entire circuit.

Claims (8)

1. A kind of 1. solar power generation emergency power supply system, it is characterised in that：It is including independent photovoltaic generating system (1) and in parallel therewith Grid-connected/off-network photovoltaic generating system (2), the independent photovoltaic generating system (1) includes the first solar cell module (101), the DC/DC converters (102) and battery (103) for boosting, in the DC/DC converters (102) and battery (103) photovoltaic controller (104) put for preventing accumulator super-charge from crossing is provided between；Grid-connected/off-network photovoltaic generation the system System (2) includes the second solar cell module (201) and combining inverter (202) for grid-connected/off-network switching, described grid-connected Inverter (202) includes DC/DC control modules and DC/AC control modules, the DC/AC control modules connection DC/DC control moulds The output end of block.
2. 2. solar power generation emergency power supply system according to claim 1, it is characterised in that：The photovoltaic controller (104) the detection control circuit for being used to provide pulse triggering signal, the fuse FU and battery that are in series with battery are included The anti-reverse diode VD that is in parallel, it is connected in parallel on the first transistor V1 of the first solar cell module output end and is connected on Second transistor V2 in circuit.
3. 3. solar power generation emergency power supply system according to claim 1, it is characterised in that：The DC/DC control modules Including PWM generation circuits and high frequency transformer TR, the PWM generation circuits both ends are connected an IR2110s driving chip respectively, The IR2110s driving chips connect four IGBT IGCTs, and the igbt transistor is connected with high frequency transformer.
4. 4. solar power generation emergency power supply system according to claim 3, it is characterised in that：The PWM generation circuits are adopted With UC3875 chips.
5. 5. solar power generation emergency power supply system according to claim 1, it is characterised in that：The DC/AC control modules Including full bridge inverter, filter circuit, grid-connected/off-network switch protecting circuit, Current Feedback Control Circuit and Voltage Feedback control Circuit processed；The full bridge inverter is made up of four igbt transistors；When the emergency power supply system carries out grid-connected Working mould During formula, the grid-connected/off-network switch protecting circuit connection Current Feedback Control Circuit, when carrying out off-network independent working mode, institute State grid-connected/off-network switch protecting circuit connection Voltage Feedback control circuit.
6. 6. solar power generation emergency power supply system according to claim 1 or 2, it is characterised in that：The photovoltaic controller (104) light-operated switch and time switch are also included.
7. 7. solar power generation emergency power supply system according to claim 1 or 2, it is characterised in that：The photovoltaic controller (104) it is connected with the display screen for display system working condition.
8. 8. solar power generation emergency power supply system according to claim 1, it is characterised in that：The combining inverter (202) ATmega64 chips are used.