DC BOX controller for Hybrid storage tanks that optimizes the current of the panels and the electrical network.
POWERBOX | DC/DC converter with MPPT | 1-2 kWp
The Power Box is an electrical device (DC/DC switching converter) that optimizes the adaptation of the power of the photovoltaic solar panels to the fixed ohmic resistance of the CC heating resistance of the Recosun hybrid electric water heater. Thanks to its own algorithm and MPPT method, the Power Box represents an equivalent load for the photovoltaic panels, regulated in such a way that the DC resistance of the thermos reaches its maximum power in all weather conditions. MPPT stands for Maximum Power Point Tracker.
The Power Box is installed between the Recosun hybrid electric thermos and the photovoltaic panels and can provide between 10 and 30% more energy per year, in the north of the Peninsula (Galicia, Asturias, Cantabria, the Basque Country) it can provide between 30 and 50% more energy. The real contribution depends on how the photovoltaic installation is executed, what inclination and orientation the photovoltaic panels have, if there are shadows, what climate zone it is, how to use the photovoltaic system and domestic hot water (ACS) / heating , etc.
The operation of the Power Box is based on a new method of optimizing the power of the photovoltaic panels connected to the resistance of the thermos. It is a patented method. The advantage of this method of load impedance matching to the internal resistance of photovoltaic panels is its simplicity and high speed of response to changing weather conditions (solar irradiation).
The Power Box offers two modes of operation:
1. Controlled DC resistor power supply mode (ON MPP)
Realized by DC/DC switching PWM regulator with MPP function. This mode is designed above all for conditions of diffuse solar radiation or for conditions of direct solar radiation in less favorable conditions (high temperature, unfavorable angle of incidence, non-homogeneous irradiation from photovoltaic panels), expressed approximately in ≤700W/m² of solar irradiation.
2. Uncontrolled power supply mode, direct connection between the PV panels and the DC resistance of the thermos (OFF MPP)
Made by means of circuits for the direct connection between the PV panels and the CC resistance of the water heater with automatic switching. The optimal value of the intensity of the PV panels is programmed. Reaching the optimum value, the Power Box automatically switches from controlled mode (1) to uncontrolled mode (2). From the set value to the maximum current, the direct connection has higher performance than the mode 1 connection (supply controlled by the regulator).
TECHNICAL DATA
- Input current for switching modes: 6.5A/6.3A
- input voltage max. 350V DC
- input current max. 10A
- input voltage min. start 85V DC
- input current min. for continuous PWM function 100mA
- Working MPPT range 85 - 350V DC
- output voltage max. 350V DC
- output current max. 10A
- Output load 1.0 kW; 1.5 kW and 2.0 kW (modulable power)
- Output voltage and current DC voltage and current
- PWM operating frequency 16kHz ±0.5kHz
- Average efficiency (2 kW power) 98.5%
- Self-consumption 2 W (during operation)
- IP45 electrical protection
- Dimensions (width x height x depth) 255 x 270 x 95 mm
- Weight 2.6kg
- Ambient temperature during operation 0 to 35 ºC
- Storage temperature -25 to +60 ºC
