Astec International Limited

Yancy Fontanilla Boncato

Vijay Gangadhar Phadke

James Sigamani

Ronnie Bachiller Gozun

Jonathan Ross Bernardo Fauni

Arlaindo Vitug Asuncion

Jessica Cabiles Magsino

Evan M Espina

An interleaved power converter includes a control circuit and multiple phase-shifted subconverters each having at least one power switch. The control circuit is coupled to the subconverters for controlling the power switches to balance currents in the subconverters over multiple periods. The control circuit includes a current compensator configured to determine a first duty cycle multiple times over the multiple periods, generate a PWM control signal having a present value of the first duty cycle for controlling the power switch of one of the subconverters during a period, determine a second duty cycle based on the present value of the first duty cycle and a previous value of the first duty cycle, and generate another PWM control signal having the second duty cycle for controlling the power switch of another one of the subconverters during the period. Other example power converters and control circuits are also disclosed.

Interpolation control for balancing currents in interleaved power converters

An electronic circuit comprises a first and second comparators and a first summer. The first comparator is configured to perform a first comparison to compare a first current reference signal with a signal representing an input current and configured to generate a first current error signal based on the first comparison. The second comparator is configured to perform a second comparison to compare a second current reference signal with the signal representing the input current and configured to generate a second current error signal based on the second comparison. The first summer is configured to adjust a first summer input error signal based on a second summer input error signal. The first summer input error signal is based on the first current error signal, and the second summer input error signal is based on the second current error signal.

Control circuits with peak current limit protection for switched mode power supplies

A control circuit for a switching power converter includes a current compensator. The current compensator is configured to receive a first current reference signal, a second current reference signal and a signal representing an input current of the switching power converter, generate a first current error signal based on the signal representing the input current and the first current reference signal for controlling at least one power switch of the power converter, generate a second current error signal based on the signal representing the input current and the second current reference signal, and adjust the first current error signal based on the second current error signal to limit the amount of current flowing through the switching power converter. Other example control circuits, switching power converters including control circuits and methods for limiting current in switching power converters are also disclosed.

According to some aspects of the present disclosure, isolated power supplies and corresponding control methods are disclosed. Example isolated power supplies include a transformer, at least one power switch coupled to the transformer, a controller, an output terminal, and a feedback circuit coupled to the output terminal to sense the output voltage and compare the sensed output voltage to a voltage reference. The power supplies include a fault detection circuit to sense the output voltage, compare the sensed output voltage to a fault reference, and modify a feedback signal when the sensed output voltage exceeds the fault reference. The power supplies also include a single isolation device coupled between the feedback circuit and the controller. The controller is operable to control the power switch based on the feedback signal and to detect a fault condition when a slew rate of the feedback signal exceeds a fault threshold slew rate value.

Power supplies having a single isolation device for feedback and fault detection

A control circuit includes a first integrator circuit corresponding to a first mode and a second integrator circuit corresponding to a second mode. The control circuit is configured to transition control of the power converter between the first mode and the second mode such that one of the first mode and the second mode is a controlling mode for a period of time and the other one of the first mode and the second mode is a non-controlling mode for the period of time, and set an output of the first integrator circuit or the second integrator circuit corresponding to the non-controlling mode to equal an output of the first integrator circuit or the second integrator circuit corresponding to the controlling mode. Other example control circuits, power converters including a control circuit, and methods for controlling a power converter are also disclosed.

Control circuits and methods for transitioning between power converter control modes

A switch controller for a variable output voltage power converter includes a pulse width modulator (PWM) output producing a pulsed signal for driving a power converter switch. A mode selector output is connected to a multiplier. A period selector output is connected to the multiplier and to a PWM input. The multiplier output is connected to another PWM input. A comparator output is connected to a period selector input. The period selector outputs a nominal cycle time to the PWM when an operating on-time state is greater than a minimum operating on-time. The period selector outputs an updated cycle time greater than the nominal cycle time when the operating on-time state is less than the minimum operating on-time causing the PWM to output a pulsed signal with the updated cycle time and a duty cycle equal to a duty cycle of an immediately preceding pulsed signal.

Dynamic operating frequency control of a buck power converter having a variable voltage output

A control circuit for controlling one or more power switches of a power converter includes a voltage control loop and a current control loop. The control circuit is configured to generate a current reference for the current control loop using the voltage control loop and an AC reference signal. The control circuit is configured to operate in at least a first mode in which a parameter of the voltage control loop is sampled only at every other zero crossing of the AC reference signal and the sampled parameter is used to generate the current reference for the current control loop. The power converter may be an AC-DC converter or a DC-AC converter (i.e., inverter). Alternatively, the voltage control loop may be sampled at every zero crossing of the AC reference signal, and/or more frequently during transient load conditions.

Control circuits for power converters

A grid-tie inverter includes a power circuit and a control circuit coupled to the power circuit. The power circuit has an input terminal for coupling to a DC power source and an output terminal for coupling to an AC power grid. The control circuit is configured to perturb an AC output current of the power circuit a first time and detect a first change in an AC output voltage of the power circuit without shutting down the power circuit, perturb the AC output current of the power circuit a second time and detect a second change in the AC output voltage of the power circuit, and shut down the power circuit in response to detecting at least the first change in the AC output voltage and the second change in the AC output voltage. Example embodiments and related methods of controlling grid-tied inverters are also disclosed.

Systems and methods for detecting islanding conditions in grid-tied inverters

A method of controlling a power converter having at least one switching device for supplying an output voltage and a load current to a load is disclosed. The method includes sensing the output voltage and sensing the load current. The method further includes controlling a duty cycle of the switching device according to the sensed output voltage and a voltage control loop when a rate of change of the load current does not exceed a threshold level. The method also includes adjusting the duty cycle of the switching device set by the voltage control loop when the rate of change of the load current exceeds the threshold level.

Growing community of inventors

Quezon, Philippines

Yancy Fontanilla Boncato