Abstract: A method and device for detecting damaging sub-harmonic frequencies in a power system, and recording data or initiating protective action. A microprocessor based sub-harmonic protection relay (S-PRO) monitors system voltages and currents from voltage and current transformers on the power system that may be present in the 5 Hz to 25 Hz frequency window. The user of S-PRO has full programming control to select bandwidths of frequencies or specific frequency components of the collected system voltages and currents. S-PRO can be user programmed to either detect the sub-harmonic power quantities and record them for future use in simulations or to initiate protective action. Protective action may include initiating output contact closure on the device to shut down equipment or to initiate corrective actions to prevent damage.

Abstract: An electrical control system for vehicles has a plurality of separate control modules which communicate via a communication bus and an operational program is installed in each of the modules so that all modules contain programming for the functions of each module. A programming and diagnostic system including a PC and a program connects into the bus so as to download the program from one of the modules for generating, modifying and viewing program logic steps using ladder logic which is then converted back Into an operating program format for communication to the modules. In addition, the status of the inputs and outputs of the modules of the apparatus can be displayed and forced using the programming and diagnostic system.

Abstract: An electrical control system preferably for vehicles such as a transit vehicle is arranged with a plurality of separate modules each receiving input from a series of inputs and each providing a series of outputs so that the modules combined receive inputs from all of the control, transducer and other input elements of the vehicle and the modules as a whole provide output to all of the controlled elements of the vehicle. The modules communicate between one another via a communication bus and an operational program is installed in each of the modules so that all modules contain programming for the functions of each module. A replacement module is generic and thus can contain any operational program and thus can be used for many different designs of the system. As supplied, the module may contain an existing program or no operational program if not yet programmed.