A method and a device for monitoring instantaneous electrical parameters of a power distribution system under load utilizing digital control means. An analog signal equivalent to such a parameter is sensed and rated down for processing by solid state components. This signal is converted into a binary coded digital signal having n digits. A plurality of digital signals is sampled and squared values with a format of 2n digits are derived from each sample. The squared values of one sampling period are accumulated to a sum value composed of 2n+m digits and the square root comprising n+k digits of the sum is taken. This value is rescaled to a true root mean square value by performing k left shifts as an accurate measurement result. The core of such device is represented by a microcomputer with built-in analog-to-digital converter.
A voltage regulator controller includes means for determining the tap position based on regulator impedance characteristics. In a preferred embodiment, the tap position determination system is embodied as part of an regulator designed to operate within a fixed percentage range of regulation (e.g. .+-.10%) with the identical number of turns between each of its series winding taps. In this environment, the regulator tap position is determined as a function of the regulator input voltage, the regulator output voltage, the regulator series winding current, system load power factor and internal regulator impedance.
A controller for a line regulation device such as a voltage regulator is provided with an interface to a removable memory module. The memory module is preferably of the memory card type which can be carried by a field engineer in a clothing pocket. When the memory card is inserted into an externally accessible slot in the controller, its presence is signaled to the controllers microprocessor. In response, the microprocessor reads user selected control parameters which are entered via the controller's front panel. Depending on the control parameters, the microprocessor updates the programming code in its internal memory, executes the code stored in the memory card while it is present but does not update its internal memory, or dumps selected status information to the memory card so that it can be analyzed at a different location.
The invention herein provides a supervisory circuit which is adapted to monitor an input signal and produce as an output signal, a parametric signal corresponding to the input signal. The circuit includes an input for receiving the input signal, and a stochastic processor coupled to the input for receiving the input signal and processing it to derive a signal that represents a parametric measure of the input signal. An output connected to said stochastic processor provides the parametric output signal as an output for supervisory purposes.
A circuit monitoring system for a distributed power network employs waveform capturing techniques for efficient and highly accurate monitoring. The system includes a plurality of circuit monitors and a control station, which is coupled to each of the circuit monitors via a multi-drop communications link. Each of the circuit monitors is disposed adjacent an associated one of the branches in the network for sensing power parameters in the branches and for generating and transmitting data representing the power parameters to the control station. The control station is used for generating monitoring commands to each of the circuit monitors to provide the system with full system control and evaluation capability. The system is capable of simultaneously sensing the waveform at each branch and sampling the waveforms for a predetermined number of sample points over an integral number of cycles so as to provide an efficient yet accurate implementation.
An integral electronic meter system diagnostics package including a microprocessor, storage memory, logic for automatically and periodically performing a pre-select series of system diagnostic tests, and recording any results which exceed predefined programmable thresholds, and display means for displaying error and/or diagnostic messages identifying selected diagnostic data and/or errors discovered in the meter tests during a predefined period.
