Systems and methods for characterization of retrofit opportunities are described. The methods may comprise computing, using at least one computing device disposed remote from a building and based at least in part on heating, ventilation and air conditioning (HVAC) runtime data associated with the building, one or more thermal characteristics of the building. In some embodiments, a model-predicted indoor temperature may be fitted against thermal data measured by a thermostat at the building. The thermal characteristic of the building may comprise a thermal insulation, an air leakage rate and/or an HVAC efficiency. The method may be used to determine, using the at least one computing device, suitability of the building for a retrofit opportunity to improve energy efficiency of the building. Determining the suitability may comprise evaluating the one or more thermal characteristics. The HVAC runtime data may be computed based on data received from a thermostat or a meter, such as an electric or a gas meter.

A switch state determining device, includes: an external terminal to which a switch is externally attached; a constant current generating part configured to generate a constant current and flow the constant current through the external terminal; a voltage comparing part configured to compare a terminal voltage of the external terminal with a threshold voltage to generate a comparison signal; an ON/OFF determining part configured to output an ON/OFF determination signal of the switch depending on the comparison signal; a threshold voltage control part configured to adjust the threshold voltage depending on a threshold voltage set value; and a level determining part configured to output a level determination signal of the terminal voltage or a terminal voltage value.

A signal generating device for generation of measurement signals for an electrical system includes a housing which features an electrically conducting material, an energy reservoir arranged in the housing, a data interface arranged at the housing and designed to receive signal data, a coupling interface arranged at the housing and coupled to the electrical system, and a signal generator arranged in the housing. The signal generator is coupled to the electrical energy reservoir, to the data interface and to the coupling interface. The signal generator is designed, based on the signal data, to generate the measurement signals and to output them via the coupling interface. A corresponding measuring device is also included.

A power factor correcting method for correcting a power factor in an alternating current power supply includes detecting zero-crossing points of an input voltage V.sub.AC of the AC power supply to obtain a period T of the input voltage V.sub.AC; generating a half-wave symmetric periodic function f(t) by using the period T; implementing a recursive low-pass filter y(t) by using the half-wave symmetric periodic function f(t), so that an output of the recursive low-pass filter y(t) matches a target reactive current I.sub.xcap(t) flowing through an X-capacitor; generating a reference current I′.sub.ref(t) for correcting the power factor by using a given reference current I.sub.ref(t) and the recursive low-pass filter y(t); and correcting the power factor by using the reference current I′.sub.ref(t). Accordingly, the reactive current of the EMI capacitor can be compensated in a high code efficiency manner.

The present disclosure is directed to systems and methods for controlling an electrical system using setpoints. Some embodiments include control methods that monitor an adjusted net power associated with the electrical system and adjust the setpoint based on a comparison of the adjusted demand to the setpoint. If the adjusted demand has not exceeded the demand setpoint, the setpoint is reduced. If the adjusted demand has exceeded the demand setpoint, the setpoint is increased.

Disclosed herein is a detection apparatus including: a resonant circuit provided with a Q-factor measurement coil and one or more capacitors to serve as a circuit for receiving pulses; a response-waveform detecting section configured to detect the waveform of a response output by the resonant circuit in response to the pulses; and a Q-factor measuring section configured to measure a Q factor of the resonant circuit from the response waveform detected by the response-waveform detecting section. It is possible to increase the precision of detection of a metallic foreign substance existing between a power transmitting side and a power receiving side.

It is described an electrical installation measuring system comprising a control and measuring device configured to be installed on an electrical panel of an electrical installation and perform at least one measure of an electrical parameter of the electrical installation depending on an electrical load connected to the electrical installation and transmit command signals along a telecommunication link. The system further comprises a variable load device connectable to the electrical installation and configured to: receive the command signals from the telecommunication link; and assume a plurality of load configurations according to the command signals.

An integrated device provides a measure of a quantity dependent on current through an electrical conductor, having: a sensing and processing sub-system; an electrical conductor conducting current; an insulating material encapsulates the sensing and processing sub-system and maintains the electrical conductor in a fixed and spaced relationship to the sensing and processing sub-system. The insulating material insulates the electrical conductor from the sensing and processing sub-system. Sensing and processing sub-system sensing circuitry includes magnetic field sensing elements adjacent the electrical conductor. The sensing circuitry provides a measure of the quantity as a weighted sum and/or difference of magnetic field sensing elements outputs caused by current through the electrical conductor adjacent the magnetic field sensing elements. A voltage sensing input senses a measure of voltage associated with the current conductor. Sensing and processing sub-system output circuitry provides an output measure of the quantity from the sensed measure of current and voltage.

A solid state drive (SSD) with improved techniques for testing power loss protection (PLP) capacitors and a method for testing PLP capacitors of SSDs is disclosed. In one embodiment, the SSD includes a memory controller and one or more non-volatile memory devices and a volatile memory device coupled to the memory controller. The SSD also includes a PLP capacitor configured to supply a first voltage to the memory controller, the one or more non-volatile memory devices, and the volatile memory device in the event of a power loss or failure of the SSD. In one embodiment, the PLP capacitor is further configured to increase the first voltage to a second voltage prior to testing the PLP capacitor. In another embodiment, the memory controller is configured to reduce a volume of data stored in the volatile memory device prior to testing the PLP capacitor.

A power factor correction circuit includes a power meter configured to measure a total harmonic distortion (THD) at an input port; a switching-type regulator that is controllable by a switch control signal in order to adjust a power factor; and a controller configured to generate the switch control signal to control the switching-type regulator to perform power factor correction, where the controller adjusts an on-time of a main switch of the switching-type regulator based on the measured THD to decrease the THD.