US 5,771,165 AGranted

Apparatus and method for charging a DC battery

AssigneeHydro-Quebec

InventorsPierre Couture, Karim Slimani, Bruno Francoeur

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Abstract

The battery charger including a power factor correcting and voltage regulating apparatus having an inductor through which current is modulated by a modulator to obtain an efficient regulation and an efficient power factor correction. According to a first embodiment, the modulator comprises two rectifying elements connected to two controllable high frequency bidirectional switch elements. According to a second embodiment, the modulator comprises a rectifying element connected to a controllable high frequency switch. According to a third embodiment, an efficient battery charger is provided. It comprises an inverter including four controllable high frequency bidirectional switch elements connected in a bridge configuration. According to a fourth embodiment, a two-part battery charger is provided. It has an indicator for indicating quality of the coupling between the two parts thereof. According to a fifth embodiment, a two-part battery charger is provided. It has the necessary means for detecting the voltage delivered at the terminals of the battery and using it for controlling its operation.

Claims44

Dependent claims

A separable two-part battery charger for supplying a direct current signal to battery connect terminals, comprising a first part and a second part, wherein:

the first part includes:
a secondary winding of an impedance matching transformer, having an output for delivering a transformed alternating current signal;
a first magnetic core part of the impedance matching transformer, which is magnetically coupled to the secondary winding;
a current rectifier for rectifying the transformed alternating current signal and delivering a rectified current signal;
and
a low pass filter means for low pass filtering the rectified current signal to supply the direct current signal to the battery connect terminals;
and
the second part includes:
a power supply means for producing a DC output voltage signal;
an inverter resonant circuit means for inverting the DC output voltage signal and delivering an alternating current signal;
a primary winding of the impedance matching transformer, having an input for receiving the alternating current signal;
a second magnetic core part of the impedance matching transformer, which is magnetically coupled to the first primary winding, the second magnetic core part being mechanically connectable to the first magnetic core part;
a current detector for detecting a current flowing through the inverter resonant circuit means and delivering a current signal indicative of the current flowing through the inverter resonant circuit means;
a current averaging means for averaging the current signal delivered by the current detector and delivering an average current signal;
a comparing means for comparing the average current signal to a current reference signal and delivering a signal indicative of a difference between the average current signal and the current reference signal, the difference being representative of quality of mechanical coupling between the first and second magnetic core parts;
and
an indicator for indicating to a user the quality of mechanical coupling between the first and second magnetic core parts, the indicator having an input for receiving the signal delivered from the comparing means.

14 more elements

A battery charger for supplying a direct current signal to battery connect terminals, comprising:

a power supply means for producing a DC output voltage signal;
an inverter means for inverting the DC output voltage signal and delivering a square voltage signal, the inverter means including four controllable high frequency bidirectional switch elements connected in a bridge configuration having two opposite input ends for receiving the DC output voltage signal, and two other opposite output ends for supplying the square voltage signal, each of the four switch elements having a gate for receiving a switch control signal at a controlled frequency determining the direct current signal supplied to the battery connect terminals;
a voltage detecting means for detecting the DC output voltage signal and delivering a voltage signal indicative of the DC output voltage signal;
a current detector for detecting a current signal at the input ends of the bridge configuration and delivering a signal indicative of the current signal;
a controlling means for controlling the four switch elements, the controlling means including:
a current averaging means for averaging the signal delivered by the current detector and delivering an average current signal indicative of an average value of the current signal;
multiplying means for multiplying the voltage signal delivered by the voltage detecting means by the average current signal delivered by the current averaging means and delivering a battery power signal indicative of a power supplied to the battery connect terminals;
a regulating means for comparing the battery power signal to a reference power signal and delivering a signal representative of a difference between the battery power signal and the reference power signal;
and
an oscillator having an output for delivering the switch control signals at the controlled frequency as a function of the signal delivered by the regulating means;
a resonant circuit having an input for receiving the square voltage signal and an output for producing an alternating current signal;
an impedance matching transformer having a primary winding for receiving the alternating current signal, and a secondary winding for delivering a transformed alternating current signal;
a current rectifier for rectifying the transformed alternating current signal and delivering a rectified current signal;
and
a low pass filter means for low pass filtering the rectified current signal and delivering the direct current signal supplied to the battery connect terminals.

12 more elements

A method for supplying a direct current signal to battery connect terminals, comprising steps of:

(a) supplying a DC output voltage signal;
(b) inverting the DC output voltage signal to produce a square voltage signal by means of an inverter means including four controllable high frequency bidirectional switch elements connected in a bridge configuration having two opposite input ends for receiving the DC output voltage signal, and two other opposite output ends for supplying the square voltage signal, each of the four switch elements having a gate for receiving a switch control signal at a controlled frequency determining the direct current signal supplied to the battery connect terminals;
(c) detecting the DC output voltage signal to produce an average voltage signal indicative of the DC output voltage signal;
(d) detecting a current signal at the input ends of the bridge configuration to produce an average current signal indicative of an average value of the current signal;
(e) controlling the four switch elements by means of the following steps:
(i) multiplying the average voltage signal by the average current signal to produce a battery power signal indicative of a power supplied to the battery connect terminals;
(ii) comparing the battery power signal, to a reference power signal to produce a signal representative of a difference between the battery power signal and the reference power signal;
and
(iii) producing the switch control signals at the controlled frequency as a function of the signal produced in step (ii);
(f) applying the square voltage signal to an input of a resonant circuit to produce at its output an alternating current signal;
(g) applying the alternating current signal to a primary winding of an impedance matching transformer to deliver at its secondary winding a transformed alternating current signal;
(h) rectifying the transformed alternating current signal to produce a rectified current signal;
and
(j) low pass filtering the rectified current signal to produce the direct current signal supplied to the battery connect terminals.

11 more elements

Method of operating a separable two-part battery charger for supplying a direct current signal to battery connect terminals, comprising steps of:

(a) providing a first part which includes:
a secondary winding of an impedance matching transformer, having an output for delivering a transformed alternating current signal;
a first magnetic core part of the impedance matching transformer, which is magnetically coupled to the secondary winding;
a current rectifier for rectifying the transformed alternating current signal and delivering a rectified current signal;
and
a low pass filter means for low pass filtering the rectified current signal to supply the direct current signal to the battery connect terminals;
(b) providing a second part which includes:
a power supply means for producing a DC output voltage signal;
an inverter resonant circuit means for inverting the DC output voltage signal and delivering an alternating current signal;
a primary winding of the impedance matching transformer, having an input for receiving the alternating current signal;
a second magnetic core part of the impedance matching transformer, which is magnetically coupled to the first primary winding, the second magnetic core part being mechanically connectable to the first magnetic core part;
(c) detecting a current flowing through the inverter resonant circuit means and delivering a current signal indicative of the current flowing through the inverter resonant circuit means;
(d) averaging the current signal delivered from step (c) and delivering an average current signal;
(e) comparing the average current signal to a current reference signal and delivering a signal indicative of a difference between the average current signal and the current reference signal, the difference being representative of quality of mechanical coupling between the first and second magnetic core parts;
and
(f) indicating to a user the quality of mechanical coupling between the first and second magnetic core parts, the indicating of step (f) being based on the signal delivered from step (e).

13 more elements

A separable two-part battery charger for supplying a direct current signal to battery connect terminals, comprising a first part and a second part, wherein:

the first part includes:
a secondary winding of an impedance matching transformer, having an output for delivering a transformed alternating current signal;
a first magnetic core part of the impedance matching transformer, which is magnetically coupled to the secondary winding;
a current rectifier for rectifying the transformed alternating current signal and delivering a rectified current signal;
and
a low pass filter means for low pass filtering the rectified current signal to supply the direct current signal to the battery terminals;
and
the second part includes:
a power supply means for producing a DC output voltage signal;
an inverter resonant circuit means for inverting the DC output voltage signal and delivering an alternating current signal, the inverter resonant circuit means including controllable high frequency bidirectional switch elements, each of the switch elements having a gate for receiving a switch control signal at a controlled frequency determining the direct current signal supplied to the battery connect terminals;
a primary winding of the impedance matching transformer, having an input for receiving the alternating current signal;
a second magnetic core part of the impedance matching transformer, which is magnetically coupled to the first primary winding, the second magnetic core part being mechanically connectable to the first magnetic core part;
a tertiary winding of the impedance matching transformer, which is magnetically coupled to the second magnetic core part, the tertiary winding being for delivering a voltage signal indicative of a voltage at the battery connect terminals;
and
a controller for controlling the switch elements as a function of the voltage signal delivered by the tertiary winding.

12 more elements

Method of operating a separable two-part battery charger for supplying a direct current signal to battery connect terminals, comprising steps of:

(a) providing a first part which includes:
a secondary winding of an impedance matching transformer, having an output for delivering a transformed alternating current signal;
a first magnetic core part of the impedance matching transformer, which is magnetically coupled to the secondary winding;
a current rectifier for rectifying the transformed alternating current signal and delivering a rectified current signal;
and
a low pass filter means for low pass filtering the rectified current signal to supply the direct current signal to the battery terminals;
(b) providing a second part which includes:
a power supply means for producing a DC output voltage signal;
an inverter resonant circuit means for inverting the DC output voltage signal and delivering an alternating current signal, the inverter resonant circuit means including controllable high frequency bidirectional switch elements, each of the switch elements having a gate for receiving a switch control signal at a controlled frequency determining the direct current signal supplied to the battery connect terminals;
a primary winding of the impedance matching transformer, having an input for receiving the alternating current signal;
a second magnetic core part of the impedance matching transformer, which is magnetically coupled to the first primary winding, the second magnetic core part being mechanically connectable to the first magnetic core part;
a tertiary winding of the impedance matching transformer, which is magnetically coupled to the second magnetic core part, the tertiary winding being for delivering a voltage signal indicative of a voltage at the battery connect terminals;
and
(c) controlling the switch elements as a function of the voltage signal delivered by the tertiary winding.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/904,583Filed 6 Aug 1997 · division
Priority: 5 Jun 1996
Granted: 23 Jun 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

H02M 1/4208
Circuits or arrangements for compensating for or adjusting power factor in converters or inverters: arrangements for improving power factor of AC…
H02J 7/06
Regulation of charging current or voltage: using discharge tubes or semiconductor devices
H02J 7/933
Regulation of charging or discharging current or voltage: the cycle being controlled or terminated in response to electric parameters
H02J 50/12
Using inductive coupling: of the resonant type