SUN Series Grid Tie Power Inverter

                   User Instructions for Model SUN-250G-IP65

u  ‘SGPV’ (Small Grid Tie Photovoltaic System)

l  The only plug and play small grid tie photovoltaic system

l  The stackable small grid tie photovoltaic system

l  Out Door Installation Design, IP65 Waterproof

Pic1  SUN-250G-IP65 GRID TIE INVERTER

u  INTRODUCTION

The small type solar grid tie power inverter can obtain the solar energy from solar panel, and can tie to the grid through its output cable with no extra equipment. The installation is very convenient and reliable.

 We call the system combining with small solar grid tie power inverter and solar panels as ‘SGPV’. The system includes solar panels and small type grid tie power inverter. Solar panels can be mono silicon, polygon silicon, non-crystal film or any other material that can transform solar energy to electric energy. The power of grid tie inverter should be matched to the power of solar panels connected. So the power of SGPV is defined by its solar panels, it can be standardization according to the actual using.

The AC output of the inverter can be connected to home grid directly, when the home grid is run by the conventional electric network. The small grid tie inverter monitors the volume, frequency and phase of the home grid, then produce a pure sine wave that the frequency and phase are as same as the grid's, and the volume is a bit higher than the grid's, then using the current controlled PWM method to control the output power to the grid. The small grid tie inverter just puts out power when the home grid is on.

When the sun shines, the PV panel will produces DC voltage, and the grid tie inverter will change the DC voltage to AC voltage and puts out power to the home grid. When the total power of electric apparatus that are using in the house is larger than the output power of the inverters, these power from the inverters will be consumed in the house, this will slow down the power meter, otherwise, the difference of the output power of the inverter between the total used power of the apparatus will go out from the house to the out grid.

u  ADVANTAGE

There are many advantages of SGPV compare with the traditional grid tie system.

1. Low cost and easy installation - SGPV can make full use of all types of buildings’ surface that face to the sun in the city as well as fast and easy installation of solar modules and grid tie inverter. It's very low maintenance costs.

2. Free combination - SGPV can be used as a separate grid tie system and can be setup as a large solar array with many of them. The quantity of SGPV in the array is just according to your desire. If you are planning to install a grid-tie PV system, in a general way, the solar array and inverter need to be carefully matched to ensure that the inverter’s voltage and power limits are not exceeded. When you want to increase more solar panels, and if the total power of the solar panels exceeds the allocation grid inverter, it is necessary to increase the cost of a grid inverter.

3. Combination of SGPV does not interact - The traditional solar grid tie system, they offer units ranging in high power output and these units are modular so you can have multiple units operating in parallel for large solar arrays. Although, the traditional grid inverter has MPPT feature (Maximum Power Point Tracking), but the maximum power point is according to the entire series in terms of solar panels array, if the performance of a piece of solar panels in the system, for some reason, such as leaves, bird droppings, dust, shadow, etc., degrades, the performance of the entire solar power system will decrease.

SGPV has no such disadvantage. If the performance of a piece of solar panels in the system degrades, this just effects this piece itself, will not affect other SGPV in the system.

4. Improving the efficiency of the entire solar power system – In traditional grid tie system, the solar panels are connected in series, so the MPPT of the inverter is according to the total panels in series, not to every panel, but there is difference between every panel, so not every panel is working at the maximum power, this will reduce the total power of these panel in series.

But SGPV has no such disadvantage. Because every inverter of SGPV has MPPT function, so every panel is working at the maximum power, this will increase the efficiency of the entire system.

5. Low power consumption – Most of the parts in the small grid-tie inverter are digital ICs and low power MCU, so the power consumption of it is low, though the quantity of grid tie inverters is increased, but this will not increase the power consumption of the entire system.

u  INSTALLATION

The individual system of SGPV is shown in Figure 1. Installing the solar panel of the SGPV at a suitable location that sunshine can irradiate on it, connecting the cables of the solar panel to the DC input terminals of the small grid tie inverter of the SGPV(the MC4 female plug of solar panel to the MC4 male plug of inverter, and the MC4 male plug of solar panel to the MC4 female plug of inverter), connecting the AC output cable of grid inverter into the home grid, making sure that the AC output voltage of the inverter is matched with the AC voltage of the home grid, according to your location home grid AC voltage. After this, when the sun shines, the SGPV will convert the solar energy to the home grid.

There is a LED indicator at the DC input side of the inverter, it will start to twinkle with green light when the grid and DC supply is detected. This indicates the inverter is operating under normal condition. The rate of the twinkle is according to how much power is being output from the solar panels or the wind turbine. The more big output power is, the more fast the rate is. If there is no AC grid detected, the LED will be on with red light, the inverter will not put out power, this is called “Anti-Island Protection”, and if the input DC voltage is out of the rated input range of the inverter, the LED will twinkle with red light.

SGPV can be stackable, and all SGPVs are independent each other. The total power converting to the grid is the total power of all SGPVs. The installation of each SGPV is same. Connecting large quantity of SGPV to the grid, this will construct high-power grid-tie system. The picture 2 shows that 2 units SGPVs are installed to make double power of 1 unit SGPV to the AC grid.

                     Picture 2   Two units of SGPV

u  Electrical Specifications:

u  Mechanical Specifications: