Abstract: Methods and apparatus to monitor the precharging of high voltage circuits are disclosed. In one embodiment, an apparatus includes a switch that selectively enables or disables precharge current to a high voltage circuit based on a switch control signal. The apparatus also includes a comparison circuit that compares a scaled version of a circuit voltage to a reference voltage to generate the switch control signal. In one embodiment, the switch control signal is generated to enable the precharge current when the scaled version of the circuit voltage is greater than the reference voltage.

Abstract: A network access credential change request is received onto a network access credential updating system. The network access credential change request is a request to update access credentials of a network near a vehicle charge station. The new credential in the request is communicated to an electric vehicle. The network is updated with the network access credential. The vehicle is able to connect to the network with the updated credential after the network has been updated. In one embodiment, the network access credential updating system includes an application. A charge station operating entity communicates a network access credential change request for a particular network to the application. After sending the request, the charge station operating entity updates the network access credential for the network in accordance with a credential update agreement. The credential update agreement tends to afford adequate opportunity for vehicles to receive updated credentials before networks are updated.

Abstract: An eFuse for use in high voltage applications is disclosed. In one embodiment, an apparatus includes a solid-state switch having source and drain terminals connected to switch a load current from a high voltage source through a high voltage load. The apparatus also includes a sense circuit that senses a voltage between the switch source and drain terminals and turns off the switch when the voltage exceeds a selected voltage level.

Abstract: A vapor-compression multi-evaporator cooling system comprises a cooling control system and two or more evaporators each coupled to an expansion valve. Each evaporator is selectively enabled or disabled during operation. When an evaporator is enabled, the evaporator transfers heat into a working fluid within the system. When an evaporator is disabled, the evaporator does not exchange any appreciable amount of heat within the system. The cooling control system includes a cooling controller, an adjustable compressor, a condenser, and a variable speed fan that provides selectable amounts of cooling to the condenser. During operation, the cooling controller adjusts the compressor operation and fan speed to maintain stable operation of the cooling system. To compensate for enabling or disabling of evaporators, the cooling controller adjusts compressor operation and fan speed to provide more or less compression and more or less condenser cooling to maintain stable and efficient operation of the cooling system.

Abstract: A vehicle includes a vehicle mass estimator circuit. The vehicle mass estimator circuit is configurable to estimate a mass of vehicle during real-time operation of the vehicle without employing a scale or dedicated mass sensing system. The vehicle mass estimator circuit generates the vehicle mass Mv from: (1) an estimated torque or sensed torque, (2) an estimated motor angular velocity or sensed motor angular velocity, and (3) sensed acceleration or without any sensed acceleration. In one embodiment, the vehicle mass estimator circuit senses motor current during vehicle operation and estimates a mass of the vehicle using the motor current without any dedicated acceleration sensor such as an accelerometer. A motor angular velocity is estimated from the motor current. In another embodiment, the vehicle mass estimator circuit senses motor current during vehicle operation and estimates a mass of the vehicle using the motor current and acceleration information provided by an accelerometer.

Abstract: Charging apparatus and methods are provided that support multiple charging devices. In an embodiment, a charging apparatus includes a secondary signal generator (SSG) and an output circuit. The SSG receives charging control signals and generates one or more secondary charging control signals. The output circuit outputs the charging control signals to a primary charging device and the one or more secondary charging control signals to one or more secondary charging devices, thereby enabling the use of multiple charging devices in battery applications. In an embodiment, the secondary charging signals are pulse width modulated to control the current output of the secondary charging devices to avoid over-current conditions.

Abstract: A system comprises an EVSE and an electric vehicle having a precharge mode. To charge a battery, the vehicle is connected to the EVSE. In some cases, the battery is unable to energize power buses. For example, if the battery is too cold and has insufficient charge, then the battery will not energize the power buses. If the battery cannot energize the power buses, then a precharge mode is enabled. During the precharge mode, charge is pumped onto two power buses until a setpoint voltage is reached. For example, a precharge circuit pumps charge onto one power bus and a power converter pumps charge from that bus onto a second bus. Once the setpoint voltage is reached, a current source charger is enabled, and energy stored on both buses is used to facilitate the turn-on of the charger, the precharge mode is disabled, and the EVSE charges the battery.

Abstract: A characteristic, such as State Of Health (SOH) or State Of Charge (SOC), is estimated for an Energy Storage System (ESS) by supplying a pre-determined signal to the ESS, measuring a response signal output by the ESS, and obtaining an impedance spectrum of the ESS. In one example, the ESS is one of several electrochemical battery packs of an electric vehicle. The pre-determined signal is a current signal generated by a switching power converter that transfers charge from the battery pack to other battery packs or transfers charge from the other battery packs onto the battery pack. The pre-determined signal is generated without disrupting any load supplied by the battery packs. The battery pack outputs a voltage signal in response to receiving the pre-determined current signal. A processor obtains an impedance spectrum using the current and voltage signals, and thereby obtains an SOH and SOC estimate of the battery.

Abstract: A controller generates a target motor torque and target accessory power information during operation of an electric vehicle. The target motor torque and target accessory power information maintain a DC-link of the electric vehicle powertrain within a safe DC-link operating range. The DC-link has a DC-link voltage that is used to supply an accessory device and a motor. The accessory device is disposed on the electric vehicle and includes vehicle indictors, hydraulics, or any other accessory involved in the operation of the vehicle. The motor drives the vehicle. The controller receives the DC-link voltage, motor speed, desired output torque information, desired accessory power information, and the safe DC-link operating range and generates therefrom the target motor torque and the target accessory power information.

Abstract: An eFuse for use in high voltage applications is disclosed. In one embodiment, an apparatus includes a solid-state switch having source and drain terminals connected to switch a load current from a high voltage source through a high voltage load. The apparatus also includes a sense circuit that senses a voltage between the switch source and drain terminals and turns off the switch when the voltage exceeds a selected voltage level.

Abstract: Pre-loading drivetrain to minimize electric vehicle rollback and increase drive responsiveness. In an exemplary embodiment, a method includes (a) detecting that an electric vehicle is stationary, a brake is engaged, and an accelerator is not engaged, and (b) controlling a vehicle motor to transition from a first mode to a second mode in response to (a). In the first mode, the motor is controlled to output torque in response to the accelerator position, and in the second mode, the motor is controlled to output torque sufficient to preload the electric vehicle. The method also includes (c) detecting the brake is transitioning away from being engaged and the accelerator is not engaged, and (d) controlling the motor to operate in a third mode in response to (c). In the third mode the motor is controlled to output torque sufficient to maintain the electric vehicle stationary.

Abstract: A system includes a power source, a power converter, a leakage current cancelation circuit, a load, and a ground node. The power converter is coupled to the power source and supplies the load. During operation of the power converter, a common mode current flows from the load to the ground node via a leakage capacitance. The leakage current cancelation circuit receives at least one signal indicative of the common mode current and generates a leakage cancelation current that is injected into at least one node of the system. The leakage cancelation current has a magnitude opposite a magnitude of the common mode current. For example, the leakage current cancelation circuit receives supply voltage signals output by the power converter, and generates and supplies the leakage cancelation current onto input nodes of the power converter such that a current level on the ground node is between ?3.0 milliamperes and +3.0 milliamperes.

Abstract: A system comprises a plurality of power converters, a plurality of energy storage systems, a first common node, a second common node, and zero-reference voltage node. Each power converter is coupled between one energy storage system and the first and second common nodes. The system operates to regulate power between the power converters and the first and second common nodes. Each power converter is a bi-directional power converter and each energy storage system is a battery pack. In one example, the first common node is regulated to a voltage VSPAN, and the second common node is regulated to a voltage VSCN which is the mean of all voltages output by the battery packs. In another example, the first common node is regulated to a voltage ?VSPAN, and the second common node is regulated to a voltage +VSPAN. No power converter processes more than voltage VSPAN yielding high-efficiency power conversion.

Abstract: A characteristic, such as State Of Health (SOH) or State Of Charge (SOC), is estimated for an Energy Storage System (ESS) by supplying a pre-determined signal to the ESS, measuring a response signal output by the ESS, and obtaining an impedance spectrum of the ESS. In one example, the ESS is one of several electrochemical battery packs of an electric vehicle. The pre-determined signal is a current signal generated by a switching power converter that transfers charge from the battery pack to other battery packs or transfers charge from the other battery packs onto the battery pack. The pre-determined signal is generated without disrupting any load supplied by the battery packs. The battery pack outputs a voltage signal in response to receiving the pre-determined current signal. A processor obtains an impedance spectrum using the current and voltage signals, and thereby obtains an SOH and SOC estimate of the battery.

Abstract: A system includes a power source, a power converter, a leakage current cancelation circuit, a load, and a ground node. The power converter is coupled to the power source and supplies the load. During operation of the power converter, a common mode current flows from the load to the ground node via a leakage capacitance. The leakage current cancelation circuit receives at least one signal indicative of the common mode current and generates a leakage cancelation current that is injected into at least one node of the system. The leakage cancelation current has a magnitude opposite a magnitude of the common mode current. For example, the leakage current cancelation circuit receives supply voltage signals output by the power converter, and generates and supplies the leakage cancelation current onto input nodes of the power converter such that a current level on the ground node is between ?3.0 milliamperes and +3.0 milliamperes.

Abstract: A system includes a power source, a power converter, a leakage current cancelation circuit, a load, and a ground node. The power converter is coupled to the power source and supplies the load. During operation of the power converter, a common mode current flows from the load to the ground node via a leakage capacitance. The leakage current cancelation circuit receives at least one signal indicative of the common mode current and generates a leakage cancelation current that is injected into at least one node of the system. The leakage cancelation current has a magnitude opposite a magnitude of the common mode current. For example, the leakage current cancelation circuit receives supply voltage signals output by the power converter, and generates and supplies the leakage cancelation current onto input nodes of the power converter such that a current level on the ground node is between ?3.0 milliamperes and +3.0 milliamperes.

Abstract: According to a preferred embodiment of the invention, the system for managing a power system with a plurality of power components that includes power source components and power consumption components includes a central power bus, a plurality of adaptable connectors that each electrically couple to a power component and to the central power bus, and a control processor that receives the state of each power component from the respective adaptable connector and is configured to balance the voltage and current output from each power source component to provide a desired power to a power consumption component based on the received states.

Abstract: A test system includes a first, second, and third power converter and a data collection system. The test system performs load testing on the second and third power converters without requiring any external load. The first power converter is supplied by an Alternating Current (AC) source. During a test cycle, the first, second, and third power converters are controlled such that the second power converter is supplied by an output current of the first power converter and a feedback current output by the third power converter. The third power converter receives current output by the second power converter and outputs the feedback current onto the second power converter. The data collection system receives power converter test characteristics (voltage, current, and temperature information) during the test cycle without any power being dissipated by an external load. Test information is used to determine whether the second and third power converters are defective.

Abstract: A system for balancing charge within a battery pack with a plurality of cells connected in series, including a capacitor; a processor configured to select a combination of donor cells and receiver cells from the plurality of cells in one of the following two modes: (1) a first mode where the number of donor cells is equal to the number of receiver cells, and (2) a second mode where the number of donor cells is greater than the number of receiver cells; and a plurality of switches that electrically connect the capacitor to the donor cells to charge the capacitor, and that electrically connected the capacitor to the receiver cells to discharge the capacitor. The transfer of charge between cells in the plurality of cells through the capacitor balances the charge within the battery pack.

Abstract: According to a preferred embodiment of the invention, the system for managing a power system with a plurality of power components that includes power source components and power consumption components includes a central power bus, a plurality of adaptable connectors that each electrically couple to a power component and to the central power bus, and a control processor that receives the state of each power component from the respective adaptable connector and is configured to balance the voltage and current output from each power source component to provide a desired power to a power consumption component based on the received states.