Power supply systems and methods are provided. In one aspect, a power supply system includes a frame, a power input to receive input power from a power source, a power output to provide output power to a load, at least one battery module mounted in the frame and having a battery output that provides battery power, at least one power module mounted in the frame and coupled to the power input to receive the input power, coupled to the battery output to receive the battery power, and coupled to the power output to provide the output power from at least one of the battery power and the input power, a first controller coupled to the at least one power module, and a second controller, substantially similar to the first controller, coupled to the first controller, and coupled to the at least one power module, wherein each of the first controller and the second controller are configured to determine operational parameters of the power supply system and store a first set of parameters determined by the first controller and a second set of parameters determined by the second controller.

Method and apparatus for providing uninterruptible power

A system and method for combining power from DC power sources. Each power source is coupled to a converter. Each converter converts input power to output power by monitoring and maintaining the input power at a maximum power point. Substantially all input power is converted to the output power, and the controlling is performed by allowing output voltage of the converter to vary. The converters are coupled in series. An inverter is connected in parallel with the series connection of the converters and inverts a DC input to the inverter from the converters into an AC output. The inverter maintains the voltage at the inverter input at a desirable voltage by varying the amount of the series current drawn from the converters. The series current and the output power of the converters, determine the output voltage at each converter.

Distributed Power Harvesting Systems Using DC Power Sources

The invention in the simplest form is a method and apparatus for reliably protecting against island situations with one or multiple power sources connected to an electric distribution grid. The method and apparatus detects variations in the voltage and frequency of the grid. An observed change in grid voltage causes a change in output power that is sufficient to cause an even larger change in grid voltage when the utility AC power source is disconnected. An observed change in grid frequency causes a change in phase or reactive output power that is sufficient to cause an even larger change in grid frequency. If several shifts in voltage or frequency happen in the same direction, the response to the change is increased in an accelerating manner.

Anti-islanding method and apparatus for distributed power generation

An inverter is devised to avoid high-frequency voltages at input terminals and to allow good efficiency thanks to its simple and cost-optimized circuit layout. This is achieved by a method of converting a direct current voltage, more specifically from a photovoltaic source of direct current voltage, into an alternating current voltage at a frequency through a bridge circuit comprising switching elements (V 1 -V 4 ) and free-wheeling elements (D 1 -D 4 ), said switching elements (V 1 -V 4 ) being on the one side gated at the frequency and on the other side clocked at a high clock rate, a direct current voltage circuit, an alternating current voltage circuit and a plurality of free-wheeling phases being provided. It is provided that, during the free-wheeling phases, the alternating current voltage circuit is decoupled from the direct current voltage circuit by means of a switching element disposed in the direct current voltage circuit, a free-wheeling current flowing through one of the free-wheeling elements (D 1 ) in the bridge circuit when in the decoupled state.

Method of converting a direct current voltage from a source of direct current voltage, more specifically from a photovoltaic source of direct current voltage, into a alternating current voltage

A monitoring system and method for monitoring performance of individual powers sources in a distributed power source system A monitoring module is coupled to each of the power sources, or to each string of serially connected power sources, to monitor and collect data regarding current, voltage, temperature and other environmental factors at the power source The collected data is transmitted over a power line to a central analysis station for analysis Data collected from each source indicates malfunction or degradation at the source Comparison of data collected from adjacent sources filters for environmental factors impacting neighboring sources such as cloudy days for a solar panel Comparison of data collected from the same source at different times indicates soiling or degradation of the source with time or periodic events such as a moving shade from an adjacent building

Monitoring of Distributed Power Harvesting Systems Using DC Power Sources

A security apparatus adapted to a power converter, including a power converting circuit connected between a DC power source and an AC system; a phase detector circuit for detecting the voltage phase of the AC system to provide a phase detection signal; a reference signal generator circuit for generating a voltage reference in accordance with the phase detection signal; a control circuit for controlling an output voltage of the power converting circuit in accordance with the voltage reference. The security apparatus is characterized by a disturbance generator circuit for applying a disturbance to the phase detector circuit; and a detector circuit for detecting an abnormal state in which the phase or frequency of the output voltage of the power converting circuit deviates from a normal one.

Security apparatus for power converter

In a PWM control type power supply apparatus, there are provided a single-phase full-wave rectifier coupled to a power source having a low frequency, for rectifying a first AC (alternating current) voltage to produce a DC (direct current) voltage; a DC-to-AC inverter including a first pair of switching elements connected to an input terminal thereof, and a second pair of switching elements connected to an output terminal thereof and to the first pair of switching elements to constitute a bridge inverter circuit, for inverting the DC voltage into a second AC voltage to be applied to a load; and a switching controller connected to the DC/AC inverter for alternately turning ON/OFF the second pair of switching elements in response to a sync signal (SYC) in synchronism with the first AC voltage at the low frequency of the power source, and for alternately turning ON/OFF the first pair of switching elements in response to a PWM (pulse-width modulation) control signal obtained from the first AC voltage and the second AC voltage, in a PWM control mode at a high-frequency higher than the low frequency of the power source, whereby a phase of the second AC voltage is opposite to that of the first AC voltage.

PWM-controlled power supply capable of eliminating modulation-frequency signal components from ground potentials

In a PWM control type power supply apparatus, a modulation (high frequency) signal component is eliminated from an AC output. The PWM control type power supply apparatus includes: AC-to-DC converting means coupled to an AC (alternating current) power source capable of supplying a first AC voltage having a low frequency from a pair of output terminals, for converting the first AC voltage to obtain a positive DC (direct current) voltage from a positive half cycle of the first AC voltage appearing at one output terminal and a negative DC voltage from a negative half cycle of the first AC voltage appearing at one output terminal with a common voltage appearing at the other output terminal; and, DC-to-AC inverter means including a pair of first and second switching elements, and a PWM (pulse width modulation) controller for controlling switching operations of the first and second switching elements in a PWM control mode so as to invert the positive and negative DC voltage into a second AC voltage having a modulation frequency higher than the low frequency with respect to the common voltage output terminal, whereby the second AC voltage contains no modulation frequency component.

PWM power supply eliminating modulation-frequency components from ground potentials

PURPOSE:To contrive harmonic component not to be included in the grounding voltage of AC voltage due to PWM control by generating the output of the AC voltage due to the PWM control, positive/negative-symmetrically to a neutral point, in an inverter main-circuit. CONSTITUTION:When the voltage V1 of an AC power source 1 is positive, then a capacitor 4 is charged with E1 via a diode 2, and when the V1 is negative, then a capacitor 5 is charged with E2 via a diode 3. Each charge voltage E1, E2 is charged almost at tne maximum value of tne line voltage V1, and is worked as a voltage doubler rectifier circuit as it is called. The input of the DC voltage to an inverter main-circuit 6 is provided, and is converted to AC voltage by PWM control. Accordingly, harmonic component due to the high-speed switching of the harmful PWM control is not included.

Shigetoshi Higaki

Papers

Security apparatus for power converter

PWM-controlled power supply capable of eliminating modulation-frequency signal components from ground potentials

PWM power supply eliminating modulation-frequency components from ground potentials

Power supply device using pwm control

Pulsbreiten-modulierte Leistungsversorgung mit Unterdrückungsfähigkeit von Modulierungsfrequenzsignalkomponenten von Erdpotentialen.