Application of INVT GD100-PV VFD in Gurkha Nepal

Abstract: With the development of the photovoltaic industry, solar panels work more and more efficient. Meanwhile due to the exponential growth of photovoltaics, prices for PV systems have rapidly declined in recent years. So it is really a good timing to expand the photovoltaic market. GD100-PV, INVT product for photovoltaic water pump, has been kept upgrading to meet the requirements in the market. Benefited from the development of the electronic and internet, INVT has invested R & D resources for developing a new solution which makes installation simple and reliable. This article mainly introduces GD100-PV series solar pump inverter applied in a remote village in Gurkha Nepal.

Key words: GD100-PV, Photovoltaic, PV water pump, Nepal

1.Introduction

The deficit in electricity and high diesel costs affects the pumping requirements of community water supplies and irrigation; so using solar energy for water pumping is a promising alternative to conventional electricity and diesel based pumping systems. Solar water pumping is based on photovoltaic (PV) technology that converts solar energy into electrical energy to run a DC or AC motor based water pump.

There are many remote areas in Nepal where the solar energy is abundant. And for some places, the water resource is far away from where they live. So it is an efficient and economy way to use GD100-PV product to solve the problems that it is hard to get the water for living supply, irrigation and so on.

2.Background

It is a remote village in Gurkha Nepal that surrounds with mountains. The transportation there is not convenient and the steep mountain path is rugged and rough. Meanwhile, the resource of water is from mountain spring which is a bit far away from the village. So it is hard for people in village to get the water that is necessary to be used for living supply, feeding livestock, irrigation and so on, which disturbs local people a lot. The problem is solved successfully after using INVT GD100-PV inverter.

Some pictures about the local village

3.Advantages of GD100-PV series

• Be suitable for single phase and 3-phase water pump.
• Built-in MPPT controller and excellent MPPT algorithm for various photovoltaic panels.
• IP54 cabinet solution, meets various harsh outdoor environments, and can be installed in the outdoor directly.
• Inverters lower than 2.2kW support the boost module.
• Support PV input and AC grid input together, realize the switching function automatically, without human intervention.
• Include water level control logic, avoid dry run status and added full water protection.
• Start smoothly for reducing the voltage spike to motor.
• Low start voltage and wide input voltage range give more possibilities for accepting multi PV strings configuration and different type of PV module.
• Digital intelligent control can Flexibly adjust and set pump’s speed range. In addition to soft start function also can provide lightning protection, overvoltage, over current, overload protection function.
• Support GPRS module, people can operate the system by website platform or mobile phone apps.

4.Photovoltaic Systems

A photovoltaic system converts the sun’s radiation into usable electricity. It consists of the solar array and the balance of system components. PV systems can be categorized by various aspects. The process contains both physical and chemical reactions in nature, as the first step involves the photoelectric effect from which a second electrochemical process takes place involving crystallized atoms being ionized in a series, generating an electric current.

Figure 1: Principle of photovoltaic

5.Two Solutions of GD100-PV

There are 2 solutions for different rated power segment pumps, for the pumps whose powers are lower than 2.2kW,the solution is as the figure 2, for the bigger rated power pumps, the solution is as the figure 3.

For low rated power pumps ≤2.2kW, when we configure the solar panels, the PV power is enough, but the PV output voltage is not enough, which requires extra quantity of solar panels to increase the PV voltage. To solve the problem, GD100-PV supplies the boost module, and supports low PV voltage input and high DC voltage output, which can reduce the quantity of PV panels.

Figure 2: Boost module + GD100-PV

Figure 3: Auto-switch module + GD100-PV

The auto-switch module which is optional can detect the PV output voltage, and send the signal to GD100-PV, inverter will control the contactor to turn on/off the AC input.

Figure 4: Water pumping system

6.Conclusion

Due to the GD100-PV product integrates so many features, such as reducing the PV input voltage, switching power input channel between DC and AC, high IP class IP54 and so on, the end users don’t need to maintain the solar inverter any more after setting the parameters at the first time.

GD100-PV product can detect the PV voltage, and if it is less than the setting point, the driver will change the power input channel from PV to AC grid automatically. If there is only PV channel input, GD100-PV will hibernate in the weak sun light and wake up automatically in the morning.

7.Application in Gurkha Nepal

With the assistance of our salesmen and technical engineers, many people in village have installed GD100-PV inverters which really are greatly helpful for them. The local customer named Sunbridge bought two GD100-PV inverters of 18.5kW and 5.5Kw in a local government supporting project. Take 18.5Kw GD100-PV inverter for example, the configuration of solar panels are 72x310w=22320w. (72≈1.2x18500/310, ‘1.2’ is experience value which can be adjusted in actual application). The related pictures are as below.

Some pictures of the drive and pump

Reference:

[1] Operation manual of GD100-PV series solar pumping inverter of Shenzhen INVT Electric Co., Ltd.