Abstract: An electronic load module system for testing voltage sources, such as power supplies, batteries, and fuel cells, is characterized by its ability to combine multiple load modules into a single virtual load for use with a first voltage source while simultaneously allowing other load modules in the same system to independently provide a load to an additional voltage source. The load modules may be combined in various configurations without altering the internal physical structure of the system. The system includes a first load module connected with the terminals of the voltage source and an associated control module connected with the first load module to supply a drive signal to the load module. The load system also includes a second load module. The second load module may be connected with the terminals of the voltage source in parallel with the first load module, or the second load module may be connected with the terminals of a second voltage source.

Abstract: An adjustable load bank provides a load to a power source that is able to maintain a constant power and constant current as well as power factor control. The load bank utilizes various resistive and inductive elements that may be connected or disconnected as required. In operation, the load bank continuously monitors the voltage and current across the resistive and inductive elements and applies or subtracts elements as necessary via control signals in order to maintain the desired fixed total power dissipated by the load bank.

Abstract: An electronic load system for testing power supplies, batteries, and fuel cells is characterized by its ability to automatically detect a transistor failure in the load circuit. The electronic load system includes a plurality of field effect transistor (FET) modules. Each FET module includes an FET and a differential amplifier. A processor module serves as an input to the amplifier and provides a drive signal. The FET module further includes a diode and a light emitting diode that are arranged such that the light emitting diode lights when the field effect transistor fails as an open circuit.

Abstract: A constant current and constant power method and system for controlling current drawn from a voltage source uses an electronic load device such as one or more field effect transistors connected with the voltage source via a switch. The load device is configured as a resistance device. A constant resistance, a cutover voltage, and either a constant current or a constant power are set by the user for the voltage source. When the switch is closed, a fixed current is drawn from the voltage source to the load and the voltage from the source is measured. The measured voltage is compared with the cutover voltage. When the measured voltage is less than the cutover voltage, the current to the load is maintained in accordance with the measured voltage and the constant resistance. When the measure voltage exceeds the cutover voltage, the current to the load device is switched to a constant current or the load device is switched to constant power.

Abstract: A virtual parallel load bank system is characterized by a load band connected in parallel with the source terminals of a voltage source to create a specific current to be applied to the terminals. The load bank includes a plurality of loads that are selectively connected in accordance with the desired current for the voltage source. One load device is designated as a master load and a communication network is connected with the load devices to enable the master load device to communicate with the other load devices to determine which are available for connection in the virtual load bank system.

Abstract: A load device for applying an active load to a power source such as a wind turbine is characterized by an inductance and a resistive element both connected in parallel with the source. A relay is connected in series with the inductance and the resistive element and a controller is connected with the relays to selectively connect the inductance or resistive element with the source. By connecting a selected load with the power source, the source can be tested to evaluate that it is operating and performing properly.

Abstract: A transistorized load system for testing electronic power systems devices includes at least one field effect transistor that is microprocessor-controlled for simulating the current drawn by a specific product on an electronic power source. The transistorized load system is capable of accepting command information either manually or from a personal computer derived source, and determining the exact value of current drawn from the electrical power system under test. The transistorized load may accept values for a desired resistance value in ohms, and/or a desired capacitance value in farads. Once voltage is applied across the positive and negative terminals of the transistorized load, the microprocessor controls the current drawn from the device under test.

Abstract: A hybrid load system includes a dynamic electronic load module, and a plurality of passive resistive modules coupled with the dynamic electronic load module. The hybrid system includes a control system in communication with the dynamic electronic load module and the passive resistive modules for determining when and how many of the passive resistive modules should be applied in parallel with the dynamic electronic load module for creating a desired load.

Abstract: A hybrid load system includes a dynamic electronic load module, and a plurality of passive resistive modules coupled with the dynamic electronic load module. The hybrid system includes a control system in communication with the dynamic electronic load module and the passive resistive modules for determining when and how many of the passive resistive modules should be applied in parallel with the dynamic electronic load module for creating a desired load.