Telefonaktiebolaget Lm Ericsson (publ)

Fredrik Wahledow

Magnus Karlsson

Jonas Malmberg

Anders Kullman

Oscar Persson

Henrik Borgengren

Torbjörn Holmberg

Marko Leskovec

Magnus Karlsson Karlsson

The invention relates to a device, method, computer program and computer program product for determining the equivalent series resistance of a power converter having power train parameters comprising a capacitance, an inductance and the equivalent series resistance, the device comprising a resistance determining unit that obtains a ripple voltage embedded in an output voltage of the power converter, determines a ripple current based on the output voltage, the inductance and operational switching data of the power converter, and estimates the equivalent series resistance of the power converter based on the ripple voltage, ripple current and the operational switching data.

Determining the equivalent series resistance of a power converter

A controller for a switched mode power supply (SMPS) including a reference voltage signal generator to generate a variable reference voltage signal for regulating an output voltage of the SMPS, and a voltage droop control signal generator to receive a current indicator signal indicative of an output current of the SMPS, and generate an output voltage droop control signal in response to a first function and a second function of the current indicator signal. The first function is employed when the reference voltage signal generator ramps the variable reference voltage signal, and the second function is employed thereafter. The controller includes a switching control signal generator to receive a voltage indicator signal, and to generate a control signal to regulate the output voltage of the SMPS based on the voltage indicator signal, the variable reference voltage signal, and the output voltage droop control signal.

Voltage droop control in a voltage-regulated switched mode power supply

A system and method to determine a capacitance of a capacitor. In one embodiment, a power converter includes a controller coupled to an output capacitor and a power train configured to convert an input voltage to a nominal output voltage. The controller is configured to ramp up an output voltage of the power converter with a first slope and a second slope, and receive a first output current of the power converter during a first rise time associated with the first slope and a second output current of the power converter during a second rise time associated with the second slope. The controller is also configured to compute a capacitance of the output capacitor employing the first and second output currents, the first and second rise times, and the nominal output voltage.

System and method to determine a capacitance of a capacitor

A control circuit for a switched mode power supply (SMPS) has an input voltage reference voltage generator arranged to receive a signal indicative of an input voltage of the SMPS and is arranged to generate a reference signal directly proportional to the input voltage. An error signal generator of the control circuit is arranged to receive a signal indicative of an output voltage of the SMPS and arranged to generate an error signal based on the reference signal generated by the input reference voltage generator and based on the output voltage of the SMPS. A duty cycle control signal generator of the control circuit is arranged to generate a control signal, to control the duty cycle of the SMPS, in dependence upon the error signal.

Controlling a switched mode power supply with maximised power efficiency

A method of operating a switched mode power supply comprising a switched mode converter and a control arrangement. The switched mode converter converts an input voltage to an output voltage and includes a primary winding, controllable switch based circuitry connecting the input voltage over the primary winding, a secondary winding coupled to the primary winding, and an LC filter including an inductive element and a capacitive element, wherein the output voltage is obtained as the voltage over the capacitive element and a duty cycle of the switched mode converter can be controlled by controlling the switch based circuitry. The switched mode converter is controlled depending on measurements of the input and output voltages in a hybrid regulated ratio control scheme. The power of the switched mode power supply is shut off or a current thereof is limited, when a current of the switched mode power supply reaches a maximum current.

Method of operating a switched mode power supply, computer program, and switched mode power supply

A switched mode power supply comprising a switched mode converter and a controller for controlling the switched mode converter, the switched mode converter being provided for converting an input voltage to an output voltage and including, on a primary side, a primary winding and a controllable switch based circuitry connecting the input voltage over the primary winding; and, on a secondary side, a secondary winding coupled to the primary winding and a capacitive element connected over the secondary winding, wherein the output voltage is obtained as the voltage over the capacitive element. The primary winding comprises a first winding portion and at least one further winding portion and the switch based circuitry comprises controllable switches capable of controlling the duty cycle of the switched mode converter and capable of switching between a first operation state wherein the input voltage is connected only over the first winding portion and at least a second operation state wherein the input voltage is connected over the first and the at least one further winding portions, thereby enabling switching between two different transformer ratios. The controller comprises a first control arrangement connected to monitor the output voltage of the switched mode converter and operatively connected to the controllable switches to control the controllable switches to switch to thereby control the duty cycle in response to the monitored output voltage and a reference voltage using PID feedback control. The controller further comprises a second control arrangement connected to monitor the input voltage of the switched mode converter and operatively connected to the controllable switches to control the controllable switches to switch between the first and the at least second operation states in response to the monitored input voltage.

Switched mode power supply, base station, and method of operating a switched mode power supply

A voltage converter () is disclosed, which comprises a controller () operable in: a first mode to control the voltage converter so as to convert an input voltage (V) at an input () of the voltage converter to an output voltage (V) at an output () of the voltage converter; and a second mode, in which the controller () is configurable by configuration control signals () so as to change the control applied by the controller to the voltage converter. The voltage converter () also includes a power module () arranged to derive and supply an operation voltage (V) to the controller (), the power module () being arranged to derive the operation voltage from the input voltage (V) during operation of the controller () in the first mode, and a voltage source () other than the input voltage (V) during operation of the controller () in the second mode. There is also described herein a power supply system comprising one or more such voltage converters, and a method of configuring the power supply system.

Programmable voltage converter

A digital control unit generates a control signal to control a duty cycle of a switched mode power supply such that a faster response to an input voltage transient is achieved. The digital control unit comprises a feedback compensator, a feed forward compensator, a transient detector, and a controller. The transient detector receives a signal indicative of the input voltage of the switched mode power supply and detects transients on the received signal. The feedback compensator receives a signal indicative of the output voltage of the switched mode power supply and adjusts the control signal. The feed forward compensator receives a signal indicative of the input voltage of the switched mode power supply, performs a relatively fast, but coarse, adjustment of the control signal, and then performs a more accurate, but relatively slow, adjustment of the control signal.

Voltage feed-forward compensation and voltage feedback compensation for switched mode power supplies

To reduce power loss in an intermediate bus architecture power system, embodiments of the present invention provide an intermediate bus converter which converts an input voltage to an intermediate bus voltage using a converting unit; receives a signal indicative of an output of a converting unit; determines an intermediate bus voltage to reduce power loss in dependence upon the signal indicative of an output of the converting unit; generates a control signal to control the converting unit to convert the input voltage to the determined intermediate bus voltage; and generates an intermediate bus voltage in dependence upon the control signal.

Control of dynamic bus voltage in an intermediate bus architecture power system

A switching delay controller is configured to control a switching delay between the switching of first and second switching elements in a switched mode power supply. The switched mode power supply generates a feedback signal indicative of a difference between an output of the switched mode power supply and a reference for the output, and switches the first and second switching elements to convert an input voltage into an output voltage based on the feedback signal. The switching delay controller includes a switching delay calculator operable to cause a change of the switching delay for at least one switching cycle of the switched mode power supply, and a feedback signal monitor operable to monitor the feedback signal and determine a change in the feedback signal in response to the change of the switching delay by the switching delay calculator.

Switching delay controller for a switched mode power supply

To calculate a control signal for the duty cycle of a switched mode power supply (SMPS), a voltage feed forward compensator is integrated into a feedback unit. A control unit has an adder with a first input to receive a signal dependent upon an output voltage. A second input receives a signal from a feedback circuit, and an output outputs a signal comprising the sum of the signals applied to the inputs; another output outputs a control signal for controlling the duty cycle, the control signal is dependent upon the output signal from the adder; a voltage feed forward compensation signal generator calculates a compensation signal to adjust the control signal depending upon an input voltage of the SMPS; and a feedback circuit between the output of the adder and the second input of the adder calculates a compensated feedback signal and to feed the compensated feedback signal to the second input of the adder.

Feedforward digital control unit for switched mode power supply and method thereof

An isolated switched mode power supply (SMPS) is disclosed. The SMPS comprises a switching controller to generate start-up and operational switching control signals. The SMPS further includes a transformer, having a primary winding, and a full-bridge drive circuit to drive the primary winding. The full-bridge drive circuit comprises a first switching element, a boot-strap dnving circuit, and a second switching element. The switching controller is further used to start up isolated SMPS by determining a duty cycle for operational control signals and generating the start-up switching control signals.

Start-up procedure for an isolated switched mode power supply

A switched mode power supply (SMPS) comprising a feedback unit, voltage feed forward (VFF) compensation signal generator and a transient detector. A VFF compensation signal is only applied to the output of the feedback unit when a transient is detected by the transient detector on the input voltage of the SMPS, thereby saving power and computation time. The transient detector comprises a first comparator to detect that a positive transient has occurred if a difference signal is greater than a positive threshold level; a second comparator to determine if the difference signal is within a predetermined range of positive values and output a result that indicates if the difference signal is within the predetermined range of positive values; and a first calculator to detect that a positive transient has occurred if, out of a first predetermined number of consecutive results of the output of the second comparator, there is at least a second predetermined number of results indicating that the difference signal is within the predetermined range of positive values. The transient detector comprises further features for similarly detecting a negative transient.

Growing community of inventors

Färjestaden, Sweden

Fredrik Wahledow