초록 ▼

A variable speed controller is provided which utilizes a combination of pulse width modulation and fixed pulse control, such as a conventional six-step control, in order to generate multiphase sinusoidal power signals for use by downhole wellbore equipment, such as electrical submersible pumps. A co

A variable speed controller is provided which utilizes a combination of pulse width modulation and fixed pulse control, such as a conventional six-step control, in order to generate multiphase sinusoidal power signals for use by downhole wellbore equipment, such as electrical submersible pumps. A controller is utilized to monitor at least one DC voltage level of the rectifier and/or inverter circuit of a variable speed controller. The DC level is compared to an optimum DC level. A triggering threshold is established. Once the triggering threshold is surpassed, the controller is utilized to switch between a conventional six-step mode of control and a pulse width modulation mode of control in order to better respond to a positive transient voltage condition. The pulse width modulation mode of operation provides for real time counteracting of the positive transient condition. Once the controller determines that the transient condition has subsided, control is returned to the conventional six-step control mode of operation.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for supplying power to electrical power consuming subsurface wellbore equipment, comprising:(a) an input for receiving a multiphase sinusoidal power input having a frequency and amplitude;(b) a rectifier circuit for rectifying said multiphase sinusoidal power

[ What is claimed is:] [1.] An apparatus for supplying power to electrical power consuming subsurface wellbore equipment, comprising:(a) an input for receiving a multiphase sinusoidal power input having a frequency and amplitude;(b) a rectifier circuit for rectifying said multiphase sinusoidal power input circuit electrically coupled to said rectifier circuit;(c) an inverter circuit for producing a multiphase output having a selected frequency from a range of available frequencies;(d) a controller electrically coupled to said inverter circuit and said rectifier circuit for executing program instructions to moderate operations of said inverter circuit in order to develop said multiphase output having said selected frequency;(e) a control input electrically coupled to said controller for receiving commands including a value for said selected frequency from said range of available frequencies;(f) wherein said controller is operable in a plurality of modes of operation, including:(1) a fixed pulse mode of operation in which said controller executes program instructions for generating a multiphase sinusoidal output having said selected frequency by combining positive and negative pulses of fixed and uniform durations, in a predetermined manner;(2) a pulse width modulation mode of operation in which said controller executed program instructions for generating a multiphase sinusoidal output having said selected frequency by controlling said inverter circuit to generate positive and negative pulses of particular non-uniform durations and by combining said positive and negative pulses in a predetermined manner.