Danfoss Compressors Gmbh

Secop Gmbh

Motor Competence Center Holding Flensburg Gmbh

Rune Thomsen

Kristoffer Riemann Hansen

Mads Andersen

Henrik Joergensen

Niels Pedersen

Claus Schmidt

Ole Schebel Bachmann

Anders Jakob Madsen

A variable speed drive comprises a voltage filter and voltage polarity protection unit including 1) a voltage filter circuit configured for low-pass filtering a voltage of an associated DC voltage source, and 2) a voltage polarity protection circuit configured to prevent incorrect polarity parring between the variable speed drive and the associated DC voltage source; a DC power supply unit being operatively connected to the voltage filter and voltage polarity protection unit via at least a positive polarity connection; an inverter unit being operatively connected to the DC power supply unit, a controllable load dump inserted in series with the positive polarity connection between the voltage filter and voltage polarity protection unit and the DC power supply unit, and a control unit configured to control at least the DC power supply unit, the inverter unit and the controllable load dump.

Variable speed drive for a compressor module

The invention relates to a system for operating a first PEG element (PFC) and a second PEC element (PFC) in an interleaved mariner, said system comprising a first integrated circuit (IC) having a first PFC controller, a second integrated circuit (IC) having a second PFC controller, as well as a synchronization circuit (SYNC) connecting the first integrated circuit (IC) and the second integrated circuit (IC), whereas the synchronisation circuit (SYNC) is adapted to control the first integrated circuit (IC) and the second integrated circuit (IC) such that the first PFC element (PFC) and the second PFC element (PFC) are operated in anti-phase.

System for operating PFC elements in an interleaved manner

A system for protecting a power consuming circuit, the system comprising two terminals for receiving power and two terminals for providing received power. Between one of the receiving terminals and a providing terminal, a transistor is provided which is controlled by a Zener diode and to break the connection between one of the receiving terminals and a providing terminal, if a voltage over the providing terminals or the receiving terminals exceeds the breakdown voltage of the Zener diode.

System and method for protecting a power consuming circuit

An electric circuit for supplying power to a DC application is disclosed. The electric circuit comprises a DC power source () connectable to an alternator charging circuit (), an FET (T), and a capacitor () connected across the gate terminal and the source terminal of the FET (T). The drain terminal of the FET (T) is connected to a negative terminal of the DC source (). The FET (T) protects the circuit against accidental connection of the alternator charging circuit () to the DC power source () with reversed polarity, by opening a switch () of the FET (T) when this occurs. The capacitor () protects the FET (T) from being pushed into avalanche in case a load-dump transient occurs. This is because the capacitor () in this case will charge and discharge, thereby introducing a time delay before the switch () is opened. Protection against load-dump transients is thereby obtained by means of a small component with low energy dissipation. Thereby the size of the circuit is reduced and energy is conserved.

Electric circuit providing protection from transients

A method and a control unit for controlling a power level being drawn from a power source (). Based on a determined rate of change of a measured voltage () an estimated remaining runtime is calculated. The estimated remaining runtime represents a time where specific run criteria will no longer be fulfilled if the present power level is maintained. The estimated remaining runtime is compared to a threshold value, and in case the estimated remaining runtime is shorter than the threshold value, the power drawn from the power source () is decreased. Thereby the runtime for the power source () is maximised. This is particularly useful if the power source is a limited power source, such as a battery (), e.g. for running a compressor () for a movable refrigeration system (). The invention is suitable for automotive applications.

Method and a control unit for controlling a power level

A method and a control unit () for controlling a supply of power to an electrical circuit comprising a switch (). An output voltage of a first power source (), which is connected to the circuit, is measured and compared to a predefined threshold voltage. If the measured voltage is smaller than the threshold value it is determined that the switch () is in a closed state, and if the voltage is larger than the threshold value it is determined that the switch () is in an open state. The supply of power is controlled in accordance with the open/closed state of the switch (). Preferably, the electrical circuit is connected to a second power source () when the switch () is in a closed state. Power is conserved while it is ensured that sufficient power is available when needed. The invention is very suitable for supplying power to a lamp () positioned inside a refrigeration compartment (), especially when the system is battery powered.

Intelligent lighting supply

The invention concerns a method for controlling a direct voltage source with a first direct voltage source () and a voltage monitoring device (), which monitors an output voltage of the first direct voltage source () and acts upon a control device (), the control device () controlling the working state of the first direct voltage source (). Further, the invention concerns a voltage supply device () with which the method can be used. In this connection it is endeavored to reduce the risk of an increase in voltage in a circuit with several direct voltage sources. For this purpose, a second direct voltage source () produces a voltage change at the voltage monitoring device ().

Method for controlling a direct voltage source and a voltage supply device

A method and a control system for starting a motor (), in particular a motor () for driving a compressor. The rotational speed () of the motor () is measured and compared to a minimum value. In the case that &#x3c9;() is smaller than the minimum value after a predefined time interval has lapsed, the motor () is stopped, and the maximum current level to be supplied by the power source () is changed, preferably increased, before a new attempt to start the motor () is initiated. Preferably, the voltage () supplied to an electronic unit () is also measured, and in the case that it drops below a minimum voltage level, the motor () is stopped, and the maximum current level is changed, preferably decreased, before a new start attempt is initiated. It is possible to adjust the supplied current level in such a way that power is conserved while sufficient lubricated of the moving parts of the compressor is ensured.

Method and a control system for starting a motor for driving a compressor

A method for starting a battery driven motor, wherein an input voltage is measured continuously. In case the input voltage becomes smaller than a predefined minimum voltage the attempt to start the motor is stopped and the maximum permitted current level to be supplied from the battery to an electronic unit of the motor is lowered before the next attempt. This is repeated until the input voltage is larger than the minimum voltage and the motor is no longer in start-up mode. The method protects the battery from collapsing. The method is suitable for starting battery driven motors for driving compressors. The number of attempted start-up sequences may be counted and on the basis of this it may be determined that the battery is weak or that the wiring is misdimensioned. Furthermore, a control system for controlling starting of a motor.

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Loegumkloster, Denmark

Rune Thomsen