To continuously provide customers with a stable and reliable solar water pump operating experience, our company has set up dedicated solar panels in our factory to conduct rigorous on-site testing of the latest solar water pump control program. Through the efforts of our engineering team, a comprehensive program optimization and upgrade has been completed, now our performance can compete against products from well-known industry peers. The core upgrade highlights are as follows:

I. Comprehensive Optimization of Control Algorithm

• Increased search time interval, reduced step size, and improved KI parameters.

• Completed 600/700 full-condition real site testing verification.

• Significantly reduced bus voltage fluctuations, greatly improving system operational stability.

II. Specific Improvements for Weak-Light situation

• Addressing the issue of repeated undervoltage issues caused by insufficient sunlight in the early morning and late evening:

• Default undervoltage recovery after 3 minutes.

• Five consecutive undervoltage readings are considered low light, automatically extending the fault recovery delay.

• All key parameters support custom settings.

• After sunlight recovery, the fault count is automatically reset to zero, avoiding false shutdowns.
  

  
  

This upgrade effectively solves voltage fluctuations and repeated start-stop cycles in low light conditions in the early morning and late evening, making the system more adaptable to complex lighting environments and operating more smoothly and efficiently.

Welcome to upgrade to the latest version of our solar water pump control program! We always adhere to the principle of leaving all problems in the factory and bringing stability and efficiency to our customers. We will continue to optimize the program to provide you with even better solar water pump products and services.

1. Photovoltaic working principle

The photovoltaic function of a frequency converter adjusts the inverter output by changing the power of the photovoltaic panels. Its logic principle is shown in the diagram below.

2. Parameter settings

1. Set motor parameters：P4-00~P4-06.

2. Terminal settings : DI1 terminal P5-00=01 (forward operation), DI2 terminal P5-01=41 (full water tank detection valid), DI3 terminal P5-02=42 (low water well detection valid), DI4 terminal P5-03=43 (manual power supply mode switching valid), P6-00=31 (water pump control valve).

3. Photovoltaic module settings : A1-00=1 (Photovoltaic enable is effective), A1-03=Open circuit voltage (currently, we manually input the open circuit voltage according to the photovoltaic panel nameplate), A1-02=Starting voltage (this value is generally set to about 80% of the open circuit voltage), A1-04=1 (Photovoltaic power supply mode).

4. Automatic operation settings : P7-41=0 (no protection when starting the terminal), P9-17=1 (automatic recovery from undervoltage fault)

3. Functional Testing

(1) Photovoltaic panel testing

Test conditions:

Photovoltaic panels: (550W*48.9V)*13 (The photovoltaic panels are shaded, and the maximum output power of the motor is around 2kW)

Frequency converter: 7.5kW asynchronous frequency converter

Motor: 3KW asynchronous submersible pump

Test parameters:

for A1-02=540V (start-up voltage), A1-05=2s (tracking interval), A1-06=5V (hysteresis voltage), A1-07=2V (step size), A1-10=1.0, A1-11=3.0, A1-12=1.0, A1-13=3.0 

(Improving stability and fault response mechanisms)

1. Compared to before, we increased the search interval and decreased the step size, and increased the KI value. Besides testing at 600, we also tested at 700. Bus voltage fluctuations decreased, significantly improving stability. 

2. To address the issue of repeated undervoltage caused by insufficient light in the morning and evening, we defaulted to a 3-minute undervoltage recovery period. If five consecutive undervoltage occurrences occur, it's considered weak light, and a longer delay is applied for fault recovery. All parameters are configurable. Furthermore, during this process, the count is reset to zero when light returns. ( Testing VECHI、INVT、GTAKE，SIMPHOENIX undervoltage fault, with a default 3-minute delay for repeated occurrences .)
   

   
   

(2) Photovoltaic simulated power supply test

(3) Fault and terminal testing