Description:FIELD OF THE INVENTION
[001] The present invention relates to a power optimisation system for a vehicle and a method thereof.

BACKGROUND OF THE INVENTION
[002] Generally, in an electric vehicle or a hybrid vehicle, electricity stored in a main battery is used to drive the vehicle. The main battery is charged by a charger when the charger is connected to a charging source. Charging generally takes place when the vehicle is in OFF condition or in standstill condition. Typically, when a vehicle is in OFF condition or in standstill condition and the charger is connected to the vehicle, a user gets a charging status notification on an infotainment cluster of the vehicle.
[003] When the charger is connected to the vehicle and the vehicle is in OFF condition or in standstill condition, a vehicle control unit of the vehicle receives signal via proximity pilot and control pilot of the charger indicating that the charger is connected to the vehicle to charge the main battery. Power supply to the ancillary modules such as vehicle control unit, the infotainment cluster, a motor control unit, a microcontroller, etc. is either taken directly from charging source via charging lines bypassing ignition or taken from the main battery. So, all the ancillary modules are active and consumes power from the main battery or the charging source.
[004] The current consumed during the OFF condition or in standstill condition of the vehicle is termed as sleep current or quiescent current. Therefore, certain amount of power is continuously drawn by ancillary modules of the vehicle. Such ancillary power loss is not desired as it eventually leads to excessive loss of power. This also increases charging time of the main battery. So, there is a need for a system which can minimize the sleep current.
[005] Thus, there is a need in the art for a system and method which addresses at least the aforementioned problems.

SUMMARY OF THE INVENTION
[006] In one aspect, the present invention is directed towards a power optimisation system for a vehicle. The system comprises a charging unit, a vehicle control unit, a voltage regulator, an isolation circuit and a switching element. The charging unit is configured to charge a battery of the vehicle. The voltage regulator is configured to regulate a voltage supplied from an auxiliary battery to the vehicle control unit. The isolation circuit is configured to receive a CAN bus signal from the charging unit and modulate the CAN bus signal to operate the voltage regulator. The switching element activates and deactivates the isolation circuit. The vehicle control unit is configured to generate a first signal to operate the switching element to activate the isolation circuit when ignition status of the vehicle is OFF and the charging unit is connected to the battery. The vehicle control unit is configured to generate a second signal to operate the switching element to deactivate the isolation circuit when the ignition status is ON.
[007] In an embodiment of the invention, the voltage regulator regulates the voltage supplied from the auxiliary battery to a microcontroller of the vehicle control unit.
[008] In another embodiment of the invention, the isolation circuit includes an opto-coupler, a comparator and a transistor circuit.
[009] In a further embodiment of the invention, a P-channel MOSFET is configured to enable a voltage supply from the auxiliary battery to the voltage regulator when the P-channel MOSFET receives a predetermined voltage from the transistor circuit.
[010] In a further embodiment of the invention, the switching element includes a Normally Close (NC) relay.
[011] In another aspect, the present invention is directed towards a method for power optimisation of a vehicle. The method comprises a step of charging a battery of the vehicle by a charging unit. The method further comprises a step of detecting the vehicle ignition status by a vehicle control unit. The method further comprises a step of receiving a CAN bus signal from the charging unit. The step of receiving a CAN bus signal from the charging unit is performed by an isolation circuit. The method further comprises a step of generating a first signal, by the vehicle control unit, to operate the switching element to activate the isolation circuit when ignition status of the vehicle is OFF and the charging unit is connected to the battery. The method further comprises a step of generating a second signal, by the vehicle control unit, to operate the switching element to deactivate the isolation circuit when the ignition status is ON. The method further comprises a step of modulating the CAN bus signal, by an isolation circuit, to operate the voltage regulator. The method further comprises a step of regulating a voltage supplied from an auxiliary battery to the vehicle control unit, by a voltage regulator.
[012] In another embodiment of the invention, the method comprises a step of enabling a voltage supply, by a P-channel MOSFET, from the auxiliary battery to the voltage regulator when the P-channel MOSFET receives a predetermined voltage from a transistor circuit.

BRIEF DESCRIPTION OF THE DRAWINGS
[013] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a block diagram of a power optimisation system for a vehicle, in accordance with an embodiment of the present invention.
Figure 2 is a block diagram of the power optimisation system illustrating details of an Isolation Circuit, in accordance with an embodiment of the present invention.
Figure 3 is a flowchart illustrating a method for optimising power in a vehicle, in accordance with an embodiment of the invention.
Figure 4 illustrates a flow diagram depicting a method for optimising power in a vehicle, in accordance with an embodiment of the invention.
Figure 5 illustrates another flow diagram depicting a method for optimising power in a vehicle, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION
[014] The present invention relates to a power optimisation system for a vehicle and a method thereof.
[015] The power optimisation system of the present invention is typically used in a vehicle such as a two wheeled vehicle, or a three wheeled vehicle, or a four wheeled vehicle, or other multi-wheeled vehicles as required. In the present embodiment, the vehicle may be an electric vehicle or a hybrid-electric vehicle.
[016] Figure 1 illustrates a power optimisation system 100 (hereinafter referred to as ‘system 100’) for a vehicle. The system 100 includes a charging unit 110, a switching element 116, an isolation circuit 118, a voltage regulator 120, an auxiliary battery 124, a vehicle control unit 114 and a Controller Area Network (CAN) Bus 112.
[017] The charging unit 110 is connected to the vehicle via a CAN Bus 112 and configured to charge a battery of the vehicle. The CAN Bus 112 is a communication channel that allows microcontrollers, devices and ancillary modules of the vehicle to communicate with each other. When the charging unit 110 is connected to the vehicle, a CAN bus signal from the charging unit 110 is sent to the isolation circuit 118 via the switching element 116. The switching element 116 is connected to the isolation circuit 118 and configured to activate and deactivate the isolation circuit 118. The isolation circuit 118 is configured to receive a CAN bus signal from the charging unit 110 only when the isolation circuit 118 is activated by the switching element 116. The isolation circuit 110 is further connected to the voltage regulator 120. Once, the isolation circuit 118 is activated, the isolation circuit 118 modulate the CAN bus signal to operate the voltage regulator 120. The voltage regulator 120 regulates a voltage supplied from the auxiliary battery 124 to the vehicle control unit 114.
[018] In an embodiment, the switching element 116 is a Normally Close (NC) relay. As illustrated in Figure 2, the CAN Bus signal is fed to switching element 116. A relay coil of the switching element 116 is driven by a transistor-based circuit (not shown). The transistor-based circuit gets enabled or disabled based on an input received from a microcontroller 122 of the vehicle control unit 114.
[019] In an embodiment, the isolation circuit 118 includes an opto-coupler 126, a comparator 132, and a transistor circuit 128. The isolation circuit 118 is a protective circuit which acts as an interface between the two separate circuits with different voltage levels. When the isolation circuit 118 is activated by the switching element 116, the CAN Bus signal is received by an emitter side (not shown) of opto-coupler 126. In an embodiment, the CAN Bus signal is received by an emitter side (not shown) of opto-coupler 126 through a resistor (not shown) to ensure that the opto-coupler 126 does not get damaged due to an input current. The collector side (not shown) of opto-coupler 126 is pulled up to the auxiliary battery 124 via a pull up resistor (not shown) as per requirement specified for selected opto-coupler 126.
[020] The output of the opto-coupler 126 is given to a comparator 132 as an input together with a reference voltage. A power to comparator 132 is given from the auxiliary battery 124 through a resistive bridge (not shown). An output from the comparator 132 is fed to the transistor circuit 128. The transistor circuit 128 acts as an inverter as the opto-coupler 126 output is inverse with respect to the input fed to the emitter side of the opto-coupler 126.
[021] In an embodiment, a P-channel MOSFET 130 is connected between the auxiliary battery 124 and the voltage regulator 120. The P-channel MOSFET 130 receives input from the transistor circuit 128 and is switched ON when the P-channel MOSFET 130 receives a predetermined input voltage from the transistor circuit 128. The P-channel MOSFET 130 is configured to enable a voltage supply from the auxiliary battery 124 to the voltage regulator 120. A source pin (not shown) of the MOSFET 130 is connected to the auxiliary battery 124 and a drain pin (not shown) of the MOSFET 130 is connected to the voltage regulator 120 which gives 5V input supply to the voltage regulator 120. Whenever an enable pin of the voltage regulator 120 goes high, the voltage regulator 120 gives output required for microcontroller 122 supply.
[022] The vehicle control unit 114 is configured to generate a first signal to operate the switching element 116 to activate the isolation circuit 118. In an embodiment, the vehicle control unit 114 is configured to generate the first signal when ignition status of the vehicle is OFF and the charging unit 110 is connected to the battery. The vehicle control unit 114 is also configured to generate a second signal to operate the switching element 116 to deactivate the isolation circuit 118 when the ignition status is ON.
[023] Figure 3 depicts operation of the system 100 for power optimisation of the vehicle. In operation, at step 302, status of the charging unit 110 is determined. If the charging unit 110 is connected, then at step 304, the ignition status of the vehicle is determined. If the ignition status of the vehicle is OFF, then at step 306, the microcontroller 122 of the vehicle control unit 114 will be in OFF state. At step 308, the vehicle control unit 114 generates the first signal and transmits the first signal to the switching element 116. At step 310, the first signal from the vehicle control unit 114 turns OFF the switching element 116 and activates the isolation circuit 118. Since the switching element 116 is the NC relay, hence the switching element 116 activates the isolation circuit 118. At step 312, the isolation circuit 118 receives the CAN Bus Signal. After receiving the CAN Bus signal, the isolation circuit 118 modulates the CAN Bus signal. At step 314, the modulated CAN Bus signal from the isolation circuit 118 is then sent to operate the voltage regulator 120. Then at step 316, the power is supplied to the microcontroller 122 of the vehicle control unit 114 from the auxiliary battery 124. The microcontroller 122 then sends an input to an infotainment cluster (not shown) which shows charging status to a user when the charging unit 110 is connected to the vehicle.
[024] At step 304, the ignition status of the vehicle is determined. If the ignition status of the vehicle is ON, then at step 318, the microcontroller 122 of vehicle control unit 114 will be in ON state. At step 320, the vehicle control unit 114 generates the second signal and transmits the second signal to the switching element 116. At step 322, the second signal from vehicle control unit 114 turns ON the switching element 116. Since the switching element 116 is the NC relay, hence the switching element 116 deactivates the isolation circuit 118. Thus, the voltage is not supplied to the microcontroller 122 of the vehicle control unit 114 from the auxiliary battery 124.
[025] Figure 4 and Figure 5 are flow diagrams of a method 400 depicting operation of the system 100 for power optimisation of the vehicle, in accordance with an exemplary embodiment of the present invention.
[026] At step 402, the charging unit 110 is connected to the battery of the vehicle to charge the battery. At step 406, the vehicle control unit 114 detects the vehicle ignition status. At step 410, the isolation circuit 118 receives a CAN bus signal from the charging unit 110.
[027] At step 414, when the ignition status of the vehicle is OFF and the charging unit 110 is connected to the battery, the first signal is generated by the vehicle control unit 114 to operate the switching element 116 to activate the isolation circuit 118.
[028] At step 418, the vehicle control unit 114 generates the second signal when the ignition status is ON. The second signal operates the switching element 116 to deactivate the isolation circuit 118.
[029] Once the isolation circuit 118 is activated, at step 422, the isolation circuit 118 modulates the CAN bus signal to operate the voltage regulator 120. The CAN Bus signal is modulated as it passes through the isolation circuit 118 and operates the voltage regulator 120.
[030] At step 424, as depicted in Figure 5, the P-channel MOSFET 130 enables the voltage supply from the auxiliary battery 124 to the voltage regulator 120 when the P-channel MOSFET 130 receives the predetermined voltage from the transistor circuit 128. The P-channel MOSFET 130 is switched ON when the P-channel MOSFET 130 receives the predetermined input voltage from the transistor circuit 128 of the isolation circuit 118. The P-channel MOSFET 130 is configured to enable the voltage supply from the auxiliary battery 124 to the voltage regulator 120.
[031] At step 426, the voltage regulator 120 regulates the voltage supplied from the auxiliary battery 124 to the vehicle control unit 120. The voltage from the the auxiliary battery 124 is supplied to the microcontroller 122 of the vehicle control unit 114. The microcontroller 122 then sends the input to the infotainment cluster to show the charging status to the user.
[032] Advantageously, the present invention provides a power optimisation system for a vehicle which minimizes the sleep current. Even when all the ancillary modules are active in the vehicle, the present invention reduces the power consumption from the main battery or the charging source. When the ignition status of the vehicle is OFF and the charging unit is connected, the present invention provides a 5V voltage to be delivered to microcontroller of the vehicle control unit from the auxiliary battery. Thus, the present invention reduces the power consumption from the main battery. Hence, helps in improving the overall efficiency of the vehicle.
[033] The isolation circuit of the present invention acts a protective circuit. which acts as an interface between the two separate circuits with different voltage levels. Also, as per present invention, unless vehicle ignition is ON, other component in the vehicle control unit do not receive power. This ensures minimal current drawn from the main battery. Owing to present invention, the charging time of the main battery is reduced as the system and method of the present invention ensures less power consumption from the main battery.
[034] The present invention further ensures a low current usage as compared to existing design. This improves the efficiency of the vehicle control unit. Unused component of the vehicle control unit or ancillary modules will still perform well compared to component in existing design over a period of time. Since all components of the present invention are small, placement of the components in the circuit is easy as it requires minimal space and it does not increase the size of entire module.
[035] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

List of Reference Numerals
100 – System
110 – Charging Unit
112 – CAN Bus
114 – Vehicle Control Unit
116 – Switching element
118 – Isolation Circuit
120 – Voltage regulator
122 –Microcontroller
124 – Auxiliary battery
126 – Opto-coupler
128 –Transistor circuit
130 –MOSFET
132 –Comparator
400 –Method
, Claims:1. A power optimisation system (100) for a vehicle, comprising:
a charging unit (110) configured to charge a battery of the vehicle;
a vehicle control unit (114);
a voltage regulator (120) configured to regulate a voltage supplied from an auxiliary battery (124) to the vehicle control unit (114);
an isolation circuit (118) configured to: receive a CAN bus signal from the charging unit (110); and modulate the CAN bus signal to operate the voltage regulator (120);
a switching element (116) to activate and deactivate the isolation circuit (118); wherein
the vehicle control unit (114) being configured to:
generate a first signal to operate the switching element (116) to activate the isolation circuit (118) when ignition status of the vehicle is OFF and the charging unit (110) is connected to the battery; and
generate a second signal to operate the switching element (116) to deactivate the isolation circuit (118) when the ignition status is ON.

2. The power optimisation system (100) as claimed in claim 1, wherein the voltage regulator (120) being configured to regulate the voltage supplied from the auxiliary battery (124) to a microcontroller (122) of the vehicle control unit (120).

3. The power optimisation system (100) as claimed in claim 1, wherein the isolation circuit (118) comprising: an opto-coupler (126); a comparator (132); and a transistor circuit (128).

4. The power optimisation system (100) as claimed in claim 3 comprising: a P-channel MOSFET (130) configured to enable a voltage supply from the auxiliary battery (124) to the voltage regulator (120) when the P-channel MOSFET (130) receives a predetermined voltage from the transistor circuit (128).

5. The power optimisation system (100) as claimed in claim 1, wherein the switching element (116) comprises a Normally Close (NC) relay.

6. A method (200) for power optimisation of a vehicle, the method (200) comprising the steps of:
charging a battery of the vehicle, by a charging unit (110);
detecting the vehicle ignition status, by a vehicle control unit (114);
receiving a CAN bus signal, by an isolation circuit (118), from the charging unit (110);
generating a first signal, by the vehicle control unit (114), to operate the switching element (116) to activate the isolation circuit (118) when ignition status of the vehicle is OFF and the charging unit (110) is connected to the battery;
generating a second signal, by the vehicle control unit (114), to operate the switching element (116) to deactivate the isolation circuit (118) when the ignition status is ON;
modulating the CAN bus signal, by an isolation circuit (118), to operate the voltage regulator (120); and
regulating a voltage supplied from an auxiliary battery (124) to the vehicle control unit (120), by a voltage regulator (120).

7. The method (200) for power optimisation as claimed in claim 6 comprising the step of: enabling a voltage supply, by a P-channel MOSFET (130), from the auxiliary battery (124) to the voltage regulator (120) when the P-channel MOSFET (130) receives a predetermined voltage from a transistor circuit (128).