US 2014/0232344 A1 · CIRCUIT AND METHOD FOR VOLTAGE EQUALIZATION IN LARGE BATTERIES

Abstract

A battery equalization circuit is provided, comprising: a positive battery node connected to a positive terminal of a monitored battery cell contained in a battery circuit that includes a plurality of other battery cells connected in series with the monitored battery cell; a negative battery node connected to a negative terminal of the monitored battery cell; a secondary transformer coil configured to receive a square wave, the secondary transformer coil having an upper transformer node and a lower transformer node; an upper switch connected between the positive battery node and the upper transformer node; a lower switch connected between the negative battery node and the lower transformer control node; and a control circuit configured to control operation of the upper and lower switches based on a measured cell voltage between the positive battery node and the negative battery node, and a total battery voltage of the battery circuit.

Claims21

Dependent claims

A battery equalization circuit, comprising:

a first positive battery node configured to connect to a positive terminal of a first battery cell contained in a battery circuit that includes a plurality of other battery cells connected in series with the first monitored battery cell;
a first negative battery node configured to connect to a negative terminal of the first battery cell;
a first transformer coil configured to receive an output voltage of an AC generator, the first transformer coil having a first upper transformer node and a first lower transformer node;
a first upper switch connected between the first positive battery node and the first upper transformer node;
a first lower switch connected between the first negative battery node and the first lower transformer control node;
and
a control circuit configured to control the operation of the first upper switch and the first lower switch based on a first measured cell voltage between the first positive battery node and the first negative battery node, and a total battery voltage of the battery circuit.

4 more elements

A battery equalization circuit, comprising:

a first battery node configured to connect to a positive node of a first battery cell contained in a battery circuit;
a second battery node configured to connect to a negative node of the first battery cell and a positive node of a second battery cell;
a third battery node configured to connect to a negative node of the second battery cell;
a fourth battery node configured to connect to a negative node of the third battery cell;
a first transformer coil configured to receive an output voltage of an AC generator, the first transformer coil being connected between a first transformer node and a second transformer node;
a second transformer coil configured to receive the output voltage of an AC generator, the second transformer coil being connected between the second transformer node and a third transformer node;
a third transformer coil configured to receive the output voltage of an AC generator, the third transformer coil being connected between the third transformer node and a fourth transformer node;
a first switch connected between the first battery node and the first transformer node;
a second switch connected between the second battery node and the second transformer node;
a third switch connected between the third battery node and the third transformer node;
a fourth switch connected between the fourth battery node and the fourth transformer node;
a first control circuit configured to control the operation of the first switch based on a first measured cell voltage between the first battery node and the second battery node, and the total battery voltage;
a second control circuit configured to control the operation of the second switch based on the first measured cell voltage, a second measured cell voltage between the second battery node and the third battery node, and the total battery voltage;
a third control circuit configured to control the operation of the third switch based on the second measured cell voltage, a third measured cell voltage between the third battery node and the fourth battery node, and the total battery voltage of the battery circuit;
and
a fourth control circuit configured to control the operation of the fourth switch based on the third measured cell voltage and the total battery voltage;
wherein the first, second, and third battery cells are arranged in series with each other.

14 more elements

A method of equalizing a battery, including:

measuring a total voltage of a battery containing N battery cells arranged in series with each other;
determining an optimum cell voltage based on the measured total voltage and the value of N;
measuring a selected cell voltage of a selected battery cell from the N battery cells;
determining whether the measured cell voltage is less than the optimum cell voltage;
connecting the selected battery cell to a voltage output of a generator during a portion of a positive cycle of the voltage output of the AC generator, when it is determined that the measured cell voltage is less than the optimum cell voltage;
determining whether the measured cell voltage is greater than the optimum cell voltage;
and
connecting the selected battery cell to the voltage output of the generator during a portion of the negative cycle of the voltage output of the AC generator, when it is determined that the measured cell voltage is greater than the optimum cell voltage,
where N is an integer greater than 1.

6 more elements

Dependencies are inferred from the claim text.

Circuit and method for voltage equalization in large batteries

Life of this patent

Circuit and method for voltage equalization in large batteries

Life of this patent

Abstract

Claims21