Abstract: With the development of the photovoltaic industry, the working efficiency of PV panel becomes more and more high, benefited from the development of the electronic control devices, the performance of the drivers and controllers are more reliable. In some application, people need the pump working day and night, in order to increase the efficiency. If use the general solar inverter, people need to add the peripheral control devices to finish the switch circuit, make the power input from PV to AC grid. It will make the entire system more complex. And about the general solar inverter, it needs the high input PV voltage, to confirm the driver output voltage meet the rated voltage of water pump. This article will introduce a new product iMars BPD series solar inverter. This product will supply a safe and complete solution.
Key words: BPD, Photovoltaic, MPPT, PV water pump
Received the feedback information from the solar market and end-users, the price of solar panel is very expensive, they gave us the suggestion:
● Reduce the PV panel quantity
Because the general solar inverter need high DC input voltage.
● Support single phase pump.
For the civil water pump, many motors are single-phase, but the solar inverter in the market don’t support single phase, only support 3-phase.
● Support AC/DC channel input together.
In the night, there isn’t PV input energy, the pump will stop.
● Installed on the outdoor directly
The general solar inverter ingress protection is IP20, need to be installed in the control cabinet.
In order to meet the requirement from end-users, and solve the disadvantages of solar inverter in the market, INVT developed a new product BPD series, belongs to iMars product. BPD series solar inverter has a modern appearance and excellent performance. It solves the problems the users mentioned.
2.Advantages of INVT BPD series
● Be suitable for single phase and 3-phase 220V AC water pump.
● Built-in MPPT controller and excellent MPPT algorithm for various photovoltaic panels.
● High ingress protection class IP65, meet various harsh outdoor environments, and can be installed in the outdoor directly.
● Support built-in capacitor and external capacitor submersible pump and surface pump.
● Built-in boost circuit parts for reducing the PV working voltage to DC 80~120V, save the cost of solar panel and improve the working efficiency.
● 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.
● Digital intelligent control, flexible adjusting and setting running speed range.
● Start smoothly for reducing the voltage spike to motor.
● Provide lightning protection, over voltage, over current, overheat etc.
● built-in C3 filter, achieving reliable, automatic and unattended running
● One pump inverter can equip with multiple motors, support vector control.
● 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 Flexible adjusting and setting pump’s speed range. In addition to soft start function also can provide lightning protection, overvoltage, over current, overload protection function
Photovoltaic (PV) is the name of a method of converting solar energy into direct current electricity using semiconducting materials that exhibit the photovoltaic effect, A photovoltaic system employs solar panels composed of a number of solar cells to supply usable solar power. The process is both physical and chemical in nature, as the first step involves the photoelectric effect from which a second electrochemical process take place involving crystallized atoms being ionized in a series, generating an electric current.
Figure 1: Principle of Solar panel
4.Commissioning of BPD
Figure 2: Wiring diagram of BPD
a.Wire according to the diagram and check again.
● Set P00.18=1 and restore to the factory settings.
● Set P02.00 to 0 ( 3phase motor) or 1(single-phase motor)
● It’s necessary to set P04.34=0x01 if removed the capacitors of single-phase motor.
● Set the P02.01~P02.05 according to the name plate of pump.
● If remove the capacitor, the P02.04 need to set 200V.
● Set P15.29=0 and press run key, to check the water flow.
● If the running frequency o water flow is low, maybe the running direction is reversed, need to set P00.13=1 or exchange the wiring of motor.
● The running direction of single phase motor removed capacitor can only changed by setting P04.34.
b.Water flow adjust (P15.06~P15.10)
● PI parameters are used for adjusting the response speed.
● Bigger value, fast response, more fluctuant.
● Lower value, slow response, more steady.
c.Commissioning of MPPT
● P15.25: Vref initial value setting. Vref=Vdc _bus - P15.25.
● P15.26: Auto-set Vmppt upper limit and lower limit time.
Range: 0.0~10.0s. (Recommend: 1~3.0s)
d.Fault and delay time setting
● Under load protection：P15.16~P15.19
● Weak light protection：P15.20~P15.21
Figure 3: Flow chart of commissioning
Because the BPD integrates so many features, such as reduce the PV input voltage, switch power input channel between DC and AC, high IP class IP65, and so on, the end users don’t need to maintain the solar inverter any more after setting the parameters in the first time.
After sunset the light will be weak, BPD can detect the PV voltage is less than the setting point, it will change the power input channel from PV to AC grid automatically. If only PV channel input, BPD will hibernate in the weak sun light and wake up in the morning.
6.Application in site
Pump: 1.5kW / 220V / 50Hz / 6.2A / 2750rpm
Inverter: BPD1K5TN (AC)
Solar panel: POLO 300W/PC 6 PCS (6 in series)
AC power: single-phase 220V AC, 50Hz.
Address: Bangkok, Thailand
 Operation manual of BPD series solar pumping inverter of Shenzhen INVT Electric Co., Ltd.