An apparatus for converting between mechanical and electrical energy, particularly suited for use as a compact high power alternator for automotive use and “remove and replace” retrofitting of existing vehicles. The apparatus comprises a rotor with permanent magnets, a stator with a winding, and a cooling system. Mechanisms to prevent the rotor magnets from clashing with the stator by minimizing rotor displacement, and absorbing unacceptable rotor displacement are disclosed. The cooling system directs coolant flow into thermal contact with at least one of the winding and magnets, and includes at least one passageway through the stator core. Various open and closed cooling systems are described. Cooling is facilitated by, for example, loosely wrapping the winding end turns, use of an asynchronous airflow source, and/or directing coolant through conduits extending through the stator into thermal contact with the windings.

Compact high power alternator

A control system that can accommodate the wide variations in the output of a generator, such as a permanent magnet alternator, while providing an output with relatively uniform phase ripple. The control system includes a zero crossing detector and variable ramp generator for generating control signals to a switching rectifier to generate a regulated DC signal.

Controller for AC generator

A high voltage power supply (40) having a plurality of high voltage generators (50a, 50b,... 50j) that produce a controlled current in a load (24) having a capacitive component. Each high voltage generator consists of a pulsewidth-modulated (PWM) inverter, a high voltage transformer, and a high voltage full bridge rectifier. The high voltage generators are divided into three groups: Group I, Group II, and Group III. During a driving mode of power supply operation, the Group I, Group II, and Group III high voltage generators produce an output voltage (Vgen) from the power supply which exceeds a voltage (Vc) across the capacitive component of the load, causing the current in the load to increase. When the current in the load reaches a desired value, the power supply enters a tracking mode of operation. During the tracking mode, the Group I and Group II high voltage generators produce an output voltage (Vgen) from the power supply which equals the voltage (Vc) across the capacitive component of the load. The current through the load remains constant while the power supply tracks the voltage across the capacitive component of the load. The driving mode and the tracking mode are repeatedly performed, as the high voltage generators are driven by a square wave voltage (Vsw) produced by a timing generator (66). A control circuit (56) is also provided in the power supply to enable or disable additional Group II high voltage generators in response to fluctuations in an input voltage and the voltage across the load.

High voltage power supply having multiple high voltage generators

A circuit for regulating the output of a DC power supply that substantially eliminates turn-on transients induced by the switching of a silicon-controlled rectifier (SCR). A zero-crossover detector senses the AC voltage waveform of an applied power source and provides a trigger signal at the zero-crossing point. The trigger signal is applied to cause induction of the SCR's and raise the output voltage when the power supply output drops below a regulated value, and is interrupted so as to inhibit conduction of the SCR's and decrease the output voltage when the power supply output exceeds the regulated value.

Zero-crossover SCR power supply regulator

An automatic overvoltage protection circuit is provided for an electrical power supply of the type comprising a variable speed three phase alternator (50) having a permanent magnet rotor and three stator output windings (51, 52 and 53), a gated three phase rectifier bridge (60) connected to the three stator output windings and producing a d.c. output voltage, and a control circuit (120) for supplying gating signals at controlled firing angles to the gated three phase rectifier bridge. The control circuit includes first, second and third reference circuits (73, 74 and 75) each including a resonant LRC circuit and connected to a respective one of the three stator output windings, a gating logic circuit (135) connected to the first, second and third reference circuits and providing six outputs, feedback means (122) connected to receive the d.c. output voltage for generating an error voltage, and comparator and isolation means (140 and 145) connected to the gating logic circuit and to the feedback means for generating firing signals for the gated three phase rectifier bridge. The automatic overvoltage protection circuit limits the firing angle of the firing signals at high speed of the alternator to ≅59° while allowing the firing angle of the firing signals at low speed to be ≅0°. This is accomplished by deliberately selecting the Q and resonant frequency of the reference circuits to achieve this beneficial result.

Automatic overvoltage protection circuit

A circuit arrangement for the compensation of voltage variations of the electrical AC polyphase power line for an AC-DC converter (3). The invention comprises a first circuit (5) for determining the voltage variations at the input of each trigger rectifier (Th 1 , Th 2 , Th 3 ) of a converter (3) and a compensating circuit (6) for compensating the firing angle of each trigger rectifier. The compensating circuit (6) is connected to an output (7) of the first circuit (5) for determining the variations in the input voltage of each rectifier. Outputs of the compensating circuit (6) are connected to control inputs of the pulse generator (4) for controlling the firing angle of each rectifier so as to adjust the period of the firing pulses of each trigger rectifier (Th 1 , Th 2 , Th 3 ). The invention is particularly applicable to electrical DC power supplys for data processing systems.

Automatic device for compensation of AC polyphase power line voltage variations in AC-DC converters

The invention relates to an automatic device for compensating the electrical mains voltage variations (2) polyphase alternating, applied to an AC-DC converter (3). This device is characterized in that it comprises means (5) for determining the voltage variations at the input of each rectifier (Th ,, Th Application to electrical sources of continuous power, particularly for data processing systems.

Automatic device for the compensation of the voltage variations of the polyphase alternating current mains applied to an ac-dc converter

L'invention concerne un dispositif automatique de compensation des variations de tension du secteur electrique (2) alternatif polyphase, applique a un convertisseur alternatif-continu (3). Ce dispositif est caracterise en ce qu'il comprend des moyens (5) pour determiner les variations de tension a l'entree de chaque redresseur (Th,, Th 2 , Th.) a declenchement du convertisseur et des moyens de compensation (6) de l'angle d'amorcage de chaque redresseur a declenchement, ces moyens de compensation (6) etant relies a une sortie (7) des moyens (5) determinant les variations de tension d'entree de chaque redresseur, des sorties de ces moyens de compensation (6) etant reliees a des entrees de commande du generateur d'impulsions (4) qui commande l'angle d'amorcage de chaque redresseur, pour regler la periode des impulsions de declenchement de chaque redresseur (Th 1 , Th 2 , Th.) a declenchement. Application aux sources electriques d'alimentation continues, notamment pour les systemes de traitement de donnees.

Gérard André

Papers

Automatic device for compensation of AC polyphase power line voltage variations in AC-DC converters

Automatic device for the compensation of the voltage variations of the polyphase alternating current mains applied to an ac-dc converter

Dispositif automatique de compensation des variations de tension du secteur alternatif polyphasé appliqué à un convertisseur alternatif continu