# US 12,015,299 B1 · Method for recharging a vehicle battery

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- Number: US 12,015,299 B1
- Document ID: US12015299B1
- Status: Granted
- Kind: B1
- Application number: 18/581,431
- Filed: 2024-02-20
- Published: 2024-06-13
- Granted: 2024-06-18
- Earliest claimed: 2022-12-13
- Assignees: Prince Mohammad Bin Fahd University
- Applicants: Prince Mohammad Bin Fahd University
- Inventors: Ala A. Hussein; Abdulmajeed Al-Abdusalam; Hasan Ali Alseni; Meenhal Al-Najjar; Hani Quraish
- Web page: https://patentgrep.com/patent/US12015299B1

## CPC

- H02J 7/933: {the cycle being controlled or terminated in response to electric parameters}
- B60L 3/0046: {relating to electric energy storage systems, e.g. batteries or capacitors}
- B60L 3/12: Recording operating variables {; Monitoring of operating variables}
- B60L 53/51: Photovoltaic means
- B60L 53/54: Fuel cells
- B60L 58/16: responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
- B60L 58/21: having the same nominal voltage
- B60L 58/26: by cooling
- G01R 27/08: Measuring resistance by measuring both voltage and current
- H01M 10/44: Methods for charging or discharging (circuits for charging H02J7/00)
- H02J 7/02: for charging batteries from AC mains by converters
- H02J 7/80: including monitoring or indicating arrangements
- H02M 7/53871: {with automatic control of output voltage or current}
- B60L 2210/10: DC to DC converters
- B60L 2210/30: AC to DC converters
- B60L 2240/545: Temperature
- B60L 2240/547: Voltage
- B60L 2240/549: Current
- H02J 7/35: with light sensitive cells
- H02J 2105/37: exchanging power with electric vehicles [EV] or with hybrid electric vehicles [HEV]
- H02J 2207/20: Charging or discharging characterised by the power electronics converter
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)

## Abstract

A circuit for charging a rechargeable battery is described. The circuit includes a first DC voltage source, a bus capacitor Cbus, an H-bridge circuit, a rechargeable battery, a second DC voltage source, an impedance meter and a microcontroller. The impedance meter measures an impedance of the rechargeable battery. The microcontroller is connected to the impedance meter and to each gate contact. The microcontroller generates a set of drive signals that are configured to generate a sinusoidal with ripple current at an output terminal of the H-bridge circuit. The microcontroller adjusts a frequency of the sinusoidal with ripple current based on the impedance of the rechargeable battery and identifies a frequency of the sinusoidal with ripple current at which the rechargeable battery has a minimum internal impedance. The microcontroller adjusts the set of drive signals to generate the sinusoidal with ripple current at the identified frequency and recharge the rechargeable battery.

## Claims

### Claim 1

A method for recharging a vehicle battery, comprising:
connecting a first DC voltage source to an input terminal of an H-bridge circuit, wherein the H-bridge circuit comprises four transistor switches, wherein each transistor switch includes a gate contact;
connecting a microcontroller to the gate contacts of each of the four transistor switches;
connecting an output terminal of the H-bridge circuit to a positive terminal of a rechargeable battery of a vehicle;
connecting a second DC voltage source to the positive terminal of the rechargeable battery, wherein the second DC voltage source is a lead battery;
generating, by the microcontroller, drive signals configured to control the four transistor switches;
transmitting the drive signals to the gates of each of the four transistor switches, wherein the drive signals cause the H-bridge circuit to form a sinusoidal with ripple current at the output terminal of the H-bridge circuit;
measuring, by an impedance meter connected to the microcontroller, an internal impedance of the rechargeable battery, wherein the impedance meter is connected to a negative terminal of the rechargeable battery;
performing, by the microcontroller, an autosearch algorithm to identify a frequency of the sinusoidal with ripple current at which the rechargeable battery has a minimum internal impedance by iteratively incrementing the frequency by a frequency step size which has an initial large value which is decreased after each iteration by dividing the frequency step size by two;
after each iteration, measuring, by the impedance meter, the internal impedance of the battery;
calculating, by the microcontroller, a phase value of the internal impedance after each iteration;
comparing the phase value at each step of the iteration to a phase error threshold ε;
when the phase value is less than the phase error threshold ε, identifying, by the microcontroller, the frequency as a minimum frequency at which an imaginary part of the battery impedance is zero;
measuring, by the impedance meter, a phase of a voltage at the input terminal of the battery and a phase of a current between the output terminal of the H-bridge and the input terminal of the battery at each iteration;
calculating, by the microcontroller, a phase difference between the phase of the current and the phase of the voltage;
comparing the phase difference to the phase error threshold ε;
when the phase difference is greater than the phase error threshold ε, iteratively incrementing the frequency by incrementing a previous frequency fk−1 by an amount given by: −α(512/2N), where α is a sign of the phase difference, and Nis a number of the sign changes in the phase difference from k equals one to k equals k−1, where k equals an iteration number, where N equals zero at k equals one until the phase difference is less than the phase error threshold ε;
identifying, by the microcontroller, the frequency as a minimum frequency at which an imaginary part of the battery impedance is zero;
adjusting, by the microcontroller, the drive signals to generate the sinusoidal with ripple current at the minimum frequency;
transmitting, by the microcontroller, the adjusted drive signals to the gates of each of the four transistor switches;
injecting the sinusoidal with ripple current at the minimum frequency into the rechargeable battery; and
recharging the battery with the sinusoidal with ripple current at the minimum frequency.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
identifying the frequency of the sinusoidal with ripple current at which the rechargeable battery has minimum internal impedance by:
injecting a first frequency of the sinusoidal with ripple current into the rechargeable battery;
measuring, by the impedance meter, a first impedance of the rechargeable battery;
calculating, by the microcontroller, a phase value of the first impedance;
incrementing the first frequency;
measuring, by the impedance meter, a second impedance of the rechargeable battery;
measuring, by the microcontroller, a phase value of the second impedance; and
continuing to increment, by the microcontroller, each previous frequency fk−1, wherein k is an iteration number, and measure the impedance and the phase value until the phase value of the impedance is less than the phase error threshold ε.

### Claim 3 (depends on 2)

The method of claim 2, wherein the phase error threshold ε is 0.1 degrees.

### Claim 4 (depends on 2)

The method of claim 2, further comprising:
measuring, with the impedance meter, for each iteration k, the current between the output terminal of the H-bridge and the input terminal and the voltage at the input terminal of the battery;
identifying, by the microcontroller, for each iteration k, a phase of the current between the output terminal of the H-bridge and the input terminal and a phase of the voltage at the input terminal of the battery; and
calculating, by the microcontroller, each phase value by subtracting the phase of the voltage at the input terminal of the battery from the phase of the current between the output terminal of the H-bridge and the input terminal, taking the absolute value of the difference between the phase of the voltage at the input terminal of the battery and the phase of the current between the output terminal of the H-bridge and the input terminal and multiplying the absolute value of the difference by the frequency fk, for each iteration number k of the sinusoidal with ripple voltage by 360 degrees.

### Claim 5 (depends on 2)

The method of claim 2, wherein the first frequency is 100 Hz.

### Claim 6 (depends on 2)

The method of claim 2, wherein the first frequency is selected from the range consisting of 100 Hz to 500 Hz.

### Claim 7 (depends on 6)

The method of claim 6, wherein each iteration of the frequency equals a previous iteration of the frequency plus −α×256 kHz, wherein α is +1 if the impedance is capacitive and α is −1 if the impedance is inductive.