Surge Protection for Solar Pump Inverters

Surge Protective Device for Solar Pump Inverters

Created by: Glen Zhu | Updated Date: Feburary 28th, 2024

Surge Protector for Solar Pump Inverters

Surge protection for solar pump inverters is essential to safeguarding the reliability and longevity of solar-powered water pumping systems. Voltage surges, whether from lightning strikes or electrical disturbances, pose a significant risk to the sensitive electronic components of the system, particularly the solar pump inverter. Failure of the inverter can result in a complete halt of water pumping operations, leading to potential crop loss or water scarcity.

Implementing surge protective devices (SPDs) effectively shields the system from voltage spikes, ensuring uninterrupted operation and maximizing overall performance. Solar pump inverter surge protectors on both the DC and AC sides of the system, signal lines, and within combiner boxes, the risk of damage due to surges is minimized, enhancing system reliability and protecting valuable investments in solar pump technology.

What is solar pump inverter

A solar pump inverter is a device that controls the operation of a solar-powered water pump. It converts the direct current (DC) power generated by solar panels into alternating current (AC) power that is used to drive the water pump motor.

Solar pump inverters are crucial components in solar water pumping systems. These systems use solar energy to power water pumps, making them suitable for areas without access to traditional grid electricity or where using grid electricity is impractical or expensive.

Solar pump inverters are used to provide water supply in rural communities, agricultural fields, and remote industrial sites.

Solar pump inverters offer a sustainable and eco-friendly solution for water treatment systems, reducing energy consumption, and promoting the use of renewable energy sources.

How does a solar pump inverter work

Solar panels, capture sunlight and convert it into electricity through solar cells, then an inverter transforms this DC electricity into usable AC electricity to power the water pump motor.

The water pump motor draws water from various sources like underground wells or reservoirs, delivering it for irrigation, household use, or other needs.

Pipes transport the water to its destination, while a water tank stores excess water for times when sunlight is insufficient. Pump controllers regulate the pump’s operation, ensuring efficient water delivery and protecting the system from damage due to electrical irregularities or dry water sources.

Together, these components form a sustainable and reliable water pumping solution powered by solar energy.

Figure 1 – The working principle of solar pump system

Why solar pump inverter needs surge protection

Solar pump inverters are an efficient, cost-effective, and environmentally friendly way to power water pumping systems and other appliances using solar energy. Solar pump inverters play an important role in the pump systems, therefore it is worthwhile to taking necessary inverter surge protection.

Electricity supply in remote areas

Instead of using grid electricity to power a water pump, the solar pump inverters can get the energy directly from the solar panel system. Their efficient operation and ability to function under diverse environmental conditions guarantee continuous access to water, even in remote or rural areas.

Energy efficiency

Solar pump inverters make full use of renewable solar energy, allowing the inverters to work at optimum efficiency, thus reducing overall energy consumption. It contributes to environmental sustainability compared to traditional energy generation methods.

Solar pump inverters need surge protection to safeguard themselves and the associated equipment from voltage surges, which can originate from various sources such as lightning strikes, switching operations, or malfunctions within the system.

Surge protection is vital for solar pump inverters because:

Solar arrays are exposed to transient voltages due to their location and the nature of solar radiation.

Sudden increases in voltage can lead to irreparable damage to the inverter and other components.

Proper surge protection minimizes downtime and repair costs, increasing the economic viability of the system.

Surge protection for solar pump inverters

A surge in a solar pump system can cause permanent damage to the electronic component of the system, the solar pump inverter is no exception. Once it fails, the power output is stopped, the whole process is unable to work. Solar inverter surge protective devices properly guard against voltage surges, improving overall performance.

DC & AC Side SPDs for combiner boxes and inverters

Where to install inverter surge protectors is crucial. They are installed on both the DC and AC sides of central and string inverters, as well as in combiner boxes to protect signal lines. The choice between standard IEC 61643-11 type 2 SPDs and more robust type 1+2 SPDs depends on the plant’s exposure to lightning.

DC side protection typically utilizes a Y-connection DIN-rail configuration to provide common and differential mode protection, with no need for additional back-up fuses due to an optimized dynamic thermal disconnection system. On the AC side, overvoltage protection is necessary, often achieved using standard DIN-rail type 2 SPDs.

In some cases, type 1+2 AC SPDs may be preferred to ensure a longer lifetime and enhanced protection, especially in areas with a high risk of direct lightning impact, such as those with a very high isoceraunic level or at high altitudes.

Type 2 DC Surge Protection Device

They are characterized by an 8/20 µs lightning current waveform and have a short-circuit current rating up to 1000 A. Type 2 SPDs are typically used to protect the sensitive maximum power-point trackers (MPPTs) on the DC side of string inverters, which manage strings of photovoltaic (PV) panels and enable performance optimization in relation to cost.

Special multipole SPDs are required inside string inverters, and the number of poles depends on the number of MPPTs and the internal design of the string inverter.

Type 1+2 DC Surge Protection Device

Type 1+2 DC Surge Protection Devices (SPDs) are specifically designed to protect solar PV systems from voltage surges caused by lightning strikes and other electrical disturbances. These SPDs consist of two independent protective elements working together: a voltage-switching spark gap (Type 1+2 SPD) and a voltage-limiting varistor (Type 2 SPD).

Key features of Type 1+2 DC SPDs

  • Disruption of high-energy surges, such as those resulting from lightning strikes, to ground high shock and vibration resistance
  • Capacity to handle large discharge currents, typically around 12.5 kA per path
  • Space-efficient design, facilitating integration into solar PV systems
  • Ability to work in conjunction with Type 2 SPDs to provide comprehensive protection against both high-energy and low-level surges

The Application of solar pump inverters

The application of solar pump inverters is diverse and essential for various purposes. Solar pump inverters are used for power water pumps, their features such as waterproof systems, automatic water-level adjustment and detection, and off-grid functionality, make them suitable for a wide range of applications, including agricultural, industrial, and domestic use.

Figure 2 – The Solar pump inverter in Agrivoltaics

The working principle of the system involves collecting solar energy through PV panels and storing it as electricity in combiner boxes. The DC electricity is then transformed into AC electricity within the solar pump inverter to activate the water pump motor, thereby completing the irrigation process.

The point of surge protection lies in DC and AC side protection. All combiner boxes are recommended to install DC type 2 surge protective devices to protect against voltage surges. DC Type 1 surge protective device protects the main combiner box.

AC side control cabinet is equipped with type 1+2 surge protective devices. Surge protective devices could be installed in the inverter itself as an option.

This PV system can be interconnected to different data networks, data and single surge protectors are necessary to be considered.

Type 1+2 AC Surge Protection Device

A Type 1+2 AC SPD integrates features of both Type 1 and Type 2 SPDs to offer robust protection against different types of surge events. Type 1 protection is designed to handle high-energy surges from direct lightning strikes or nearby lightning activity, while Type 2 protection provides supplementary protection against transient over-voltages from internal sources or indirect lightning strikes.

Key features of Type 1+2 AC SPDs

  • AC Type 1+2 surge protection device SPD is characterized by a 10/350 µs and 8/20 µs lightning current waveform
  • Offer different discharge capacities, such as impulse discharge currents ranging from 7kA to 12.5kA for Type 1 and nominal discharge currents of 20kA for Type 2
  • Comply with IEC and EN standards, ensuring their reliability and safety in electrical systems

Suitable for protecting installations against lightning strikes and are designed for use in various power supply systems, including TN-C, TN-S, TN-C-S, TT, and IT systems

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Reliability in surge protection!

LSP’s reliable surge protection devices (SPDs) are designed to meet the protection needs of installations against lightning and surges. Contact our Experts!

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