Abstract: Systems and methods for automatically verifying that power relays have been disconnected include relays arranged between two power sources. Test nodes are positioned between the relays on each line, and feed into a detection circuit. Voltage drop resistors, voltage drop diodes, an optocoupler, and additional resistors and capacitors are used to provide voltage isolation for the detection circuit. Relays are methodically opened and closed to check the individual functioning of each relay, and a digital signal generated from the detection circuit. The design of the system with detection circuit isolation provides a safer and lower cost system for verifying that relays are operating correctly, with less costly components than traditional systems.

Abstract: Systems and methods for automatically verifying that power relays have been disconnected include relays arranged between two power sources. Test nodes are positioned between the relays on each line, and feed into a detection circuit. Voltage drop resistors, voltage drop diodes, an optocoupler, and additional resistors and capacitors are used to provide voltage isolation for the detection circuit. Relays are methodically opened and closed to check the individual functioning of each relay, and a digital signal generated from the detection circuit. The design of the system with detection circuit isolation provides a safer and lower cost system for verifying that relays are operating correctly, with less costly components than traditional systems.

Abstract: Systems and methods of improving storage and consumption of electricity according to time-based tiered criteria are disclosed. An energy storage system controlled by a processor is optionally connected to a utility power grid, a photovoltaic (PV) power source, and/or electrical loads. Time-of-use (TOU) rates (or similar tiered criteria) are input into the processor, which sets charge and discharge profiles according to the criteria, the arrangement of time windows, and the user's preferences. Energy is stored or discharged according to these profiles. Additionally, the energy storage system may record the production and consumption patterns of the user over time, and use this information to modify the profiles for enhanced performance by allowing discharge during non-peak windows. Benefits include reduced electrical cost to the user, reduced strain on the utility power grid during peak consumption hours, and enhanced performance with regard to any other criteria input into the processor.

Abstract: Implementations described herein relate to methods, apparatuses, and systems of leakage current detection. According to one implementation, a method includes initiating self-test of a resistive isolation detection circuit, the self-test configured to return a reset latched value representative of a state of the resistive isolation circuit, pulsing a latch reset signal to clear the reset latched value and a testing signal to indicate a testing state, and during the testing signal, independently determining, that a leakage current is present between a photovoltaic power conversion device positive channel and earth, and, that a leakage current is present between a photovoltaic power conversion device negative channel and earth. The method also includes operating a safety relay and indication signal responsive to the testing signal and the independent determining.

Abstract: A multi-level inverter includes a coupling to a DC power source and a coupling to an AC power source, a plurality of capacitors arranged to create a set of nodes, and a plurality of switches located between the capacitors and the AC power source. Switches are configured to create an AC bypass in which the capacitors coupled to the DC power source may be isolated from the AC power source. The AC bypass is utilized as one of the switching states in a switching sequence that provides enhanced performance including but not limited to reduced electromagnetic interference and ripple.