Part Number: Solar-Breaker-Reference-Design
RESIDENTIAL SOLAR BREAKER REFERENCE DESIGN
**For development reference only, not a product for sale**
The Residential Solar Breaker Reference Design combines two functionalities: a relay driver using the HV9901 and a power monitor using the MCP39F511A. It uses the HV9901 to drive a relay which enables the user to connect/disconnect the solar inverter from the grid connection. The MCP39F511A allows the user to monitor the real time power (both active and reactive) from the solar inverter. The power monitoring stage uses the Power Monitor Utility software for measurement through a USB connection to the board. The Power Monitor Utility software is used to calibrate and monitor the system. The software offers an automatic step-by-step calibration process that can be used to quickly calibrate power meters.
Application Features:
- Protects solar microinverter from fluctuations in grid voltages by relay disconnect
- Offers high temperature operation with high reliability as mounted under solar
Panels
Reference Design Features:
- Input Voltage : 195Vac to 264Vac
- RMS Current: Up to 15A (through the relay)
- External Relay Connect/Disconnect Signal
- Input Power Measurement
- Optically Isolated Digital signals for control and status
The key microchip components on the reference design are as follows:
- HV9901 Relay Driver with adjustable pull-in and hold currents it is used to connect / disconnect the on board relay
- MCP39F511A Power Monitoring IC to monitor power delivered by the inverter.
- MCP2221 USB to I2C converter to monitor the power using external GUI.
- MCP9701 Temperature Sensor helps monitor driver temperature since the driver is placed under the solar panel
- MCP6021 Amplifier used by the MCP39F911 for averaging in signal processing.
- MCP1754 LDO is a supply for the energy monitoring of the MCP39F911.
Overview
Microchip has developed the Residential Solar Breaker Reference Design featuring the HV9901, as an example reference breaker solution for single phase residential solar installations. All the Reference Design components, including the HV9901, are rated to 125°C, a critical feature for these systems as they are required to operate in the high temperature environment of the solar panel. This higher rating helps to ensure long operating life of these systems in this harsh environment. The energy tracking is supported by MCP39F511A. Power monitoring in solar installations provides multiple benefits to the customer like fault monitoring to detect a faulty inverter or panel which could cause hazardous situations and alerts in case of drop in performance. Provision for additional safety and robustness comes from the ability to install the MCP9701, which can be used to adjust the performance due to over temperature conditions (like disconnecting the inverter from the load in case of excessive temperature.)
For additional details and design files please visit the reference design page.