Solar insolation varies through the day. Because of this variation, a motor connected directly to the Solar array is likely to trip every time the available power from the array is lesser than what is required to run the motor. However, when the motor is connected to the array through a Solar pump drive (also called Solar pump controller), the Solar pump controller varies the motor speed based on the input Solar power available. The output of the pump varies based on the motor speed (which is in turn varied based on the Solar power available). In this manner, the pump is run from Solar power without using batteries.
REdrive series of high efficiency Solar MPPT Pump drives make it possible to ‘Solar enable’ pumps for irrigation or drinking water supply with support for different HP and head ratings of the pumps. These designed & made in India drives are available in the following models
Designed with Solar application as the primary focus, REdrive series of pump controllers can easily be configured for a class of motor types, thereby reducing on field installation complexity. There is no more need for back EMF programming for individual motors. The proprietary drive algorithm – which uses Field Oriented Control (FOC) approach, operates the motor at its most efficient point at a given input power. This results in better Pump Output Per Available Solar Watts. Our fast-tracking MPPT algorithm ensures the maximum power available is extracted from the Solar array. The pumps with Redrives installed start earlier in the day and can run even in low Solar power. REdrives come with extensive protections. For example, it is possible to add more Solar Panels (deliberate ‘oversizing’ of the array) if required – the drives will safely limit the output as per the rating of the motor. The comprehensive protection and monitoring of various parameters of operation protects the motors and drives from catastrophic failures, resulting in increased reliability,. REdrives come integrated with Modbus communication over RS485. The drives support remote monitoring, remote access, remote control and over-the-air firmware upgrade.
No Back EMF programming
For a Class of Motors only configure-
Output Current and Voltage waveforms of REdrive running a PMSM motor
High efficiency with advanced FoC Motor control
The drives incorporate Smart protection for higher reliability and long operational life
The Drives support Modbus (over RS485)
| Component | Remarks |
|---|---|
| Solar modules | Wp ( Watt Peak) as per Motor HP. The REdrives can be used with Solar array of any size as long as the input Voltage limits are met. |
| Solar pump controller | Drives for the Motor based on Motor HP. REdrives need to be only configured for a class of motors. |
| Motor + Pump combo | HP of Motor based on LPD (Litres per Day) required and Head. REdrives automatically adjust to deliver the best flow under a given Head and Solar power availability. The configurable current limit can be adjusted based on a class of motor requirements. |
| Surge Protection devices | To protect against induced effects of lightening on Solar modules. |
| DC MCB | For DC isolation |
| Remote monitoring systems | Most Govt. projects specify RMS and necessitates maintaining data on cloud. REdrives support Modbus protocol. Contact us for RMS device and cloud storage of data. |
| Type of Motor | Details | Converting to Solar |
|---|---|---|
| Legacy Pumps and Motors operating on grid | Typically 3Phase, 50Hz, AC Induction motors | Requires input of 585V or higher from the Solar array to run the motors at full frequency |
| AC Induction motors built for Solar | Different winding to support 3Phase , lower Voltage compared to legacy pumps. | Requires lesser input Voltage – so more suited for using mass produced Solar modules |
| PMSM (Permanent Magnet Synchronous Motors) | Specifically designed for Solar application : Typically 3 Phase, upto 250 Hz. | PMSM is also a kind of AC motor. Requires drives to deliver 3 Phase output from Solar modules. |
| Motor Type | Frequency: Upto 250 Hz,# of phases: 3Ph 1. PMSM( Permanent Magnet Synchrounous Motors) 2. AC Induction motor specially wound for Solar with Lower Voltage requirement 3. Legacy 3Ph Induction motors operating at 380/415Vac - NO. Use 5HP drive for these motors with Boost Stage (Voltage input from Solar Panels must be 590V or higher to run motor at full frequency for 3Ph 50Hz, AC Induction Motors) | Frequency: Upto 250 Hz,# of phases: 3Ph 1. PMSM( Permanent Magnet Synchrounous Motors) 2. AC Induction motor specially wound for Solar with Lower Voltage requirement 3. Legacy 3Ph Induction motors operating at 380/415Vac - NO. Use 5HP drive for these motors with Boost Stage (Voltage input from Solar Panels must be 590V or higher to run motor at full frequency for 3Ph 50Hz, AC Induction Motors) | Frequency: Upto 250 Hz,# of phases: 3Ph 1. PMSM( Permanent Magnet Synchrounous Motors) 2. AC Induction motor specially wound for Solar with Lower Voltage requirement 3. Legacy 3Ph Induction motors operating at 380/415Vac |
| Solar input | Typ 1kW, upto 200Voc , 3/4/5 modules . ( AC induction motors will have a higher input Voltage requirement.) | Typ 3kW, Upto 450Voc, 9/10 modules. ( AC induction motors will have a higher input Voltage requirement.) | Typ 5kW, Upto 800Voc, 15/16 modules |
| Minimum Solar Voltage to operate Pump start Voltage | 65V | 150V | 265V |
| MPPT Efficiency | > 99.5% | > 99.5% | >99.5% |
| Overall efficiency of the Inverter | > 97% | > 97% | > 97% |
| Maximum Output Phase Current | 12A | 12A | 12A |
| Output frequency | Upto 250Hz | Upto 250Hz | Upto 250Hz |
| Communication Configuration of parameters like Motor type, RMS Voltage, Frequency etc | Through Modbus Modbus ascii protocol using a PC based utility | Through Modbus Modbus ascii protocol using a PC based utility | Through Modbus Modbus ascii protocol using a PC based utility |
| Remote monitoring | Supports Isolated Modbus port (RS485) for connecting RMS devices. | Supports Isolated Modbus port (RS485) for connecting RMS devices. | Supports Isolated Modbus port (RS485) for connecting RMS devices. |
| Remote firmware upgrade | Secure, encrypted Firmware can be delivered to the device for Remote Over-the-air firmware upgrade | Secure, encrypted Firmware can be delivered to the device for Remote Over-the-air firmware upgrade | Secure, encrypted Firmware can be delivered to the device for Remote Over-the-air firmware upgrade |
| Float switch interface | Switch to turn off motor on 'Tank full' indication | Switch to turn off motor on 'Tank full' indication | Switch to turn off motor on 'Tank full' indication |
| Dimensions (Height X Width X Depth) inclusive of mounting flange in mm | 195 X 175 X 131 | 195 X 175 X 131 | 224 X 204 X 145 |
| Enclosure | IP20 rated enclosure, Fan cooled | IP20 rated enclosure, Fan cooled | IP20 rated enclosure, Fan cooled |
| Indications | [1] 16X2 LCD for Motor and Solar parameters [2] LEDs to show Pump status (Pump On, Fault, Tank Full) [3] Buttons ( 4 numbers) for configuration / settings | [1] 16X2 LCD for Motor and Solar parameters [2] LEDs to show Pump status (Pump On, Fault, Tank Full) [3] Buttons ( 4 numbers) for configuration / settings | [1] 16X2 LCD for Motor and Solar parameters [2] LEDs to show Pump status (Pump On, Fault, Tank Full) [3] Buttons ( 4 numbers) for configuration / settings |
| Ports | 1. PV +Ve & -Ve terminals, 2. Three Phase output - RYB 3.RS 485 output with 5V power line for external RMS 4. Float switch input. | 1. PV +Ve & -Ve terminals, 2. Three Phase output - RYB 3.RS 485 output with 5V power line for external RMS 4. Float switch input. | 1. PV +Ve & -Ve terminals, 2. Three Phase output - RYB 3.RS 485 output with 5V power line for external RMS 4. Float switch input. |
| Operating Temperature | Ambient temperature upto 50 Deg C | Ambient temperature upto 50 Deg C | Ambient temperature upto 50 Deg C |
| Protections | a. Short Circuit / Inter-Phase fault of Motor b. Phase Open c. PV reverse d. Dry run, e. Pump clogging f. High torque current g. High temperature auto back off | a. Short Circuit / Inter-Phase fault of Motor b. Phase Open c. PV reverse d. Dry run, e. Pump clogging f. High torque current g. High temperature auto back off | a. Short Circuit / Inter-Phase fault of Motor b. Phase Open c. PV reverse d. Dry run, e. Pump clogging f. High torque current g. High temperature auto back off |
Still have question?
Yes. Amberroot’s Solar VFDs have algorithm to run 3 Phase PMSM (Permanent Magnet Synchronous Motors ) and AC induction motors. The type of motor can be selected at start up / at the time of connection. Amberroot’s Solar Pump Drives automatically determine the parameters to be used. It is also possible to select values of parameters like Maximum Voltage, Maximum Torque current etc using the interface provided with the display of the units.
Solar is a variable source of energy. The following conditions affect the operational freqeuncy of the motor when used with a Solar array. [1] Is sufficient power available? With a given power level in the input of the Solar pump drive, it is possible to run the pump motor at a particular frequency. To run at full frequency, full rated power needs to be delivered to the motor, which may be available from the Solar array only at peak afternoon sunshine. Higher array size will make it possible to run the motor at full freqeuncy longer and also start up earler in the day. [2] Is the required Voltage available ? Depending on the motor Voltage rating, the motor may not be able to be run at full frequency even if sufficient power is available. For example, in a 3kW Solar array meant to power a 3phase 415VAC induction motor, let us say, 10 Solar PV panels of 330Wp each are connected in series with a Vmpp ( Voltage at Maximum Power Point) at ~ 370V. Even if the Solar pump drive is able to meet the power requirements for the motor to run at full frequency- the Voltage required ( 415 X √2 = 587V) is not met and therefore the dive cannot run the motor at full freqeuncy. The required DC Voltage to run the motor at full freqeuncy exceeds the Open circuit Voltage of the array ( ~ 440V) . In this case 10 Panels in series is not sufficient. Amberroot’s VFDs provide an input Voltage BOOST stage that boosts the Voltage from the Solar array at maximum power point to the required Voltage to run the motor at full frequency.
Solar Pump drives are meant to drive water pumps : water pumps are particularly well suited for Solar aplication. Since the output of water can vary – afterall a water tank can be used as a buffer between the water requirement and the pump output, Solar VFDs can run the pump motors at different speeds depending on the Solar power availability and the pump output varies through the day. However the same VFD is proposed to be used to run other motors in a farm like Chara Cutting machines . ( Universal Pump Controllers) . These machines may have different starting torque requirements, and characteristics of the load. Amberroot provided an additional output filter to run these machines – typically driven by 3 Phase AC induction motors.
For 3 Phase input AC , a Diode and Rectifier stage is required to convert to DC voltage as an input to the Solar pump drive. The drive can then run PMSM / specialy wound AC induction motors ( with lower operating Voltage ) or 3 Phase AC motors. The output Voltage of the Diode / Rectifier stage will exceed the ratings of our 3HP or 1 HP Solar pump drives.and therefore , the 5HP drive needs to be used for all 3 Phase motors less than 5HP.
