Generator with inverter - special design for agriculture

It is widely known that power generators power various devices. But can they control them at the same time while minimizing costs and losses?
Read the case study describing the recent execution of the generator set controlling the water pump.

Place: agricultural crop of about 100ha, PL, Kuyavian-Pomeranian, no electric utilities in the area
Date of execution: 2016

Purpose: Enable precise and lossless watering of any areas without damaging crops and relocating water cannons

Problem: water pumps belong to a group of devices that consume up to 6x more electricity during start-up compared to continuous operation. The area does not have electrical utilities, and installation of grid would generate unnecessary costs, time and many arrangements with the energy industry.

Assumptions:

Precise watering of any cultivation areas, without water losses outside them
Ease of control
Minimizing costs that are not necessary for the investor's production activity
Independence from the availability of mains power
Possibility of expanding the system with additional pumps together with auxiliary devices such as water cannons set permanently, without the need to have another power source

We proposed a solution consisting in the use of a generator set with an inverter controlling a water pump. This solution allows for smooth, lossless and easy control of the water pressure in response to the need to change the watering area (by changing the frequency of the generated current), allows the unit to be moved and easily connected to other pumps on the cultivation area, and above all neutralizes the impact of increased power consumption when starting the pump on the requirements for the generator set.

Brief specification of the generator set:

The device is additionally equipped with a 22kW inverter to smoothly regulate the speed of the submersible pump using a knob or digital setting device. In addition, protection against: pump idling, pump overload, pump overcurrent switch. The device is equipped with 63A sockets for pump connection, 63A, 32A, 2x16A sockets for power consumption, generator with AVR and ECU (voltage regulator and speed regulator), pressure measurement.

LTP power : 44 kVA

LTP power : 35 kW

rated current: 58 A

voltage: 400V / 230V

frequency: 50 Hz

generator

make: Stamford

model: PI 144 J

production country: United Kingdom

power (40c, 1000m ASL): 40 kVA

power (27C, 1000m ASL): 44 kVA

voltage stabilization level: ± 1 %

poziom stabilizacji napięcia: ± 1 %

protection class: IP 23

insulation class: H

engine

make: PERKINS

model: 1103A-33TG1

production country: United Kingdom

power: 41.3 kW

Inverter: LG IS7 22 kW, 3 phase - shortened specification:

The iS7 series inverters - this is the latest solution from LG/LS, which compared to the previous series of frequency converters is much more versatile in terms of motor control properties and has implemented complex algorithms that guarantee high parameters and precision of operation of the machines and devices controlled by them. The iS7 is a completely new generation of frequency inverters for very demanding applications and responsible control systems.

Power - 22 kW

Current - 45 A

Power supply - 3-phase, 50/60 Hz

Standard equipment of the iS7 inverter:

• 8 digital inputs
• analog current input 4-20mA
• analog voltage input -10 ~+10V
• 2 analog outputs (voltage and current)
• 4 multifunctional outputs
• built-in RS485 / Modbus RTU interfaces

The standard in the iS7 is a built-in class A anti-interference filter (for industrial applications) up to and including 22kW, which we can turn off if necessary. For capacities greater than 22kW, we offer external filters typically dedicated and manufactured to the parameters required by LS converters for each of the device's capacities. In addition to filters, all inverters in the standard have a DC choke, limiting harmonic interference, improving the power factor and significantly extending the operating time of power modules.