Harold Wells Associates, Inc. Patent applications |
Patent application number | Title | Published |
20150097504 | Electrical apparatus and control system - In a system that receives power from an electric power grid, a variable frequency AC drive has an output connected to an AC electric motor, and an input connected to the power grid. The motor is in 1 connection with a load, and the AC drive includes an active converter having a predetermined maximum apparent power capacity. The converter is coupled to a controller programmed to regulate reactive power generation and consumption of the variable frequency AC drive so that the drive produces reactive power when the converter is utilizing less than its maximum apparent power capacity. This reactive power is fed to the power grid. A device monitors current and voltage in the power grid and calculates power factor, which is then used as a feedback to an external controller that generates a reactive power reference signal intended to control the system's power factor. The controller is programmed to respond to the signal, controlling power generation and consumption so that the combination of reactive power and real power does not result in apparent power exceeding the maximum capacity of the active converter and avoids generating reactive power that would result in a leading power factor for the system. | 04-09-2015 |
20120205119 | PUMP CONTROL DEVICE, OIL WELL WITH DEVICE AND METHOD - A method of operating an oil well comprises applying through a regenerative variable frequency drive AC electrical energy from a power grid to an AC electric motor to operate a drive mechanism of an oil well pump. The motor speed is regulated in a manner to optimize fluid production and maximize the operational life of the drive mechanism, decreasing motor speed by transferring the electrical energy to the power grid and increasing motor speed by transferring the electrical energy from the power grid to the motor. The drive mechanism has a predetermined stroke cycle and, over the course of each stroke cycle, the motor is operated at different regulated speeds initiated when the drive mechanism is at a predetermined position. | 08-16-2012 |