Design of solar photovoltaic power generation coin-operated unattended electric vehicle charging station

Considering that electric vehicle coin-operated charging stations must be connected to the mains to charge electric vehicles that are out of power in time, and there is no one on duty at the charging station 24 hours a day, a coin-operated unattended electric vehicle charging station using solar photovoltaic power generation is designed. This paper analyzes and explains in detail the design, applicable sections, and usage methods of photovoltaic coin-operated unattended diversified electric vehicle charging stations. At the same time, the charging station is also suitable for urban areas and sections with mains electricity to reduce the impact of power consumption on the mains electricity, and has certain promotion significance and application prospects.

1. Introduction

At present, in China's second-tier and third-tier cities and below, electric bicycles have become one of the main means of transportation for people to go out. The embarrassing situation of electric bicycles running out of power during outings often occurs, and the heavy body of electric bicycles is time-consuming and laborious to drive manually, so people have to push the electric bicycles forward when they are out of power. As the contradictions escalate, small electric vehicle charging stations have appeared, and coin-operated electric vehicle charging stations have also been born, but the situation that electric vehicles cannot replenish electricity in time still exists. The problem is whether everyone will bring their own charger when going out. Without a suitable charger, electric vehicles cannot be charged. In addition, in the suburbs or sparsely populated roads, there is no convenient charging station for electric vehicles to charge at any time, and it is even more impossible to have a 24-hour supply of city electricity for people to use.

As a new type of energy supply system, solar photovoltaic power stations have been increasingly widely used since the 21st century. Electric vehicle photovoltaic power stations use solar photovoltaic power generation technology to timely replenish electric energy for electric vehicles on the premise of obtaining power generation and collection from solar panels. The chargers used by electric vehicles with different voltages are different. The diversified design of electric vehicle charging stations provides three DC voltages and 220V AC voltage for electric vehicles to choose from, ensuring the safety of electric vehicles during charging. In view of the difficulty of manual supervision in suburban areas, photovoltaic coin-operated unattended diversified electric vehicle charging stations not only solve the problems of difficult city power supply and mismatched chargers, but also eliminate the waste of manpower caused by manual supervision.

2. Design of photovoltaic coin-operated unattended diversified electric vehicle charging station

According to the design requirements of the charging station, this system is divided into two parts, the photovoltaic power station and the electric vehicle power supply system.

A. Structural design of photovoltaic power station

A small ground photovoltaic power station is set up in a conspicuous roadside location where there is no mains power supply, sufficient sunlight and no obstructions. Two 1650mm*990mm components arranged in series can meet the power requirements of the daily charging station (taking the charging time of each electric vehicle as 30 minutes and charging 30 electric vehicles per day as an example).

[page]B. Structural design of electric vehicle power supply system

The structural design of this part is divided into three parts:

The protection part of the power supply system (protective cover, LED lighting, pinhole camera), as shown in Figure 1. The protective cover has a certain curvature and width, riveted to the upper part of the power supply system, which can protect the entire power supply system from wind and rain. There is a lighting LED light above the protective cover to facilitate the existence and use of the charging station at night. There is a pinhole camera at the bottom of the protective cover for anti-theft monitoring;

The charging part of the power supply system consists of a coin input part (coin input, banknote input, coin output, amount selection), a charging indication part (charging time display, charging indicator light, voice speaker), and a charging connector plug part.

The coin entrance can only accept one-yuan coins, the banknote entrance can accept up to five-yuan banknotes, and the coin exit can only accept one-yuan coins. A single charge of one yuan takes 10 minutes and the driving distance is 2 kilometers. A charge of two yuan takes 25 minutes and the driving distance is 5 kilometers. A charge of three yuan takes 40 minutes and the driving distance is 10 kilometers. The maximum charging time is 40 minutes.

The charging time display will prompt the charging time and the remaining charging time from the beginning of charging; the charging indicator light is divided into three colors: red, yellow and green, indicating the start of charging, charging and charging completion respectively;

The charging connector plug has five voltage power supplies, namely DC 36V, 48V, 60V and AC two-pin 220V plug, three-pin 220V plug. If the user brings their own charger, they can use the AC 220V plug for charging. Otherwise, they can use the three different voltage chargers provided to choose the appropriate voltage type for charging.

The distribution box part of the power supply system (distribution box, fixed base) is designed with an anti-theft lock, with a keyhole and handle on the outside, and the staff is in charge of the distribution box key. After opening the box, the interior is divided into two parts, namely the distribution cabinet part and the coin storage part, both with internal locks. The distribution cabinet part, which contains circuit components such as inverters and batteries, occupies 3/4 of the entire distribution box. After opening the external lock, the maintenance personnel also have the power to open the lock of the distribution cabinet part and can perform daily maintenance on the interior of the distribution cabinet; the coin storage part occupies 1/4 of the interior of the distribution box. If the maintenance personnel also have the power to take away the coins, the three keys can be handed over to the maintenance personnel at the same time. Otherwise, the coin custodian has the power to open the coin storage part lock and the external lock at the same time, and does not have the power to open the distribution cabinet.

The fixed base is connected to the cement foundation through anchor bolts to fix the entire charging system.

C. Charging sequence

The first step is to put the coins into the corresponding coin slot, and press the amount selection button to determine the amount used for a single charge. If change is required, the coin outlet will automatically find the corresponding coin. The coin slot for incomplete coins and counterfeit coins will automatically identify them, and will not accept coins, making the charging invalid;

Step 2: After selecting the charging amount, the red light of the charging indicator will turn on, and there will be a voice prompt to start charging. Open the automatically locked flap of the charging connector plug and find a suitable charger for charging.

Step 3: After the charger is connected to the charging part and the electric vehicle, the indicator light of the charging part turns yellow and there is a voice prompt that charging is in progress.

Step 4. When the charging time is up, the indicator light of the charging part will turn green and there will be a voice prompt that charging is complete. Please unplug the charger and the power will be automatically cut off and no more charging will be performed.

Step 5. Unplug the charger, put it back in place, and close the automatically locking flap of the charging part. The charging is now complete.

3. Application prospects

Electric vehicles are advocated by the country because of their environmental protection, energy saving, noiselessness and convenience. Electric vehicles are rapidly popularized throughout the country and have become the mainstream means of transportation in cities and rural areas. They are also the most popular, energy-saving and environmentally friendly green travel vehicles with a huge number. Traditional electric vehicle charging stations rely solely on city electricity for power sources. In some suburban roads or roads where there is no city electricity available at any time, the establishment of electric vehicle charging stations has become an impossible task in people's eyes. Moreover, these remote roads require manual duty to provide power to electric vehicle charging stations at any time, guard and protect the safety of charging stations and the impact of natural weather on them. Based on the limitations of traditional electric vehicle charging stations, this paper combines the application of solar photovoltaic power generation to design a diversified electric vehicle charging station that uses solar photovoltaic power generation as a source of electricity. At the same time, this charging station also has the characteristics of anti-theft, waterproof, free of duty and simple daily maintenance, which can alleviate the severe situation of electric energy. This paper conducts a detailed analysis and practice of the structural design, applicable environment and use method of photovoltaic coin-operated free-duty diversified electric vehicle charging station, so that it has the physical function of self-protection, is easy to use, one-time deployment, and lifelong benefits, making the application of photovoltaic charging stations more extensive.