Energy converter and electromechanical apparatus

• US 8,258,734 B2
• Filed: 02/08/2010
• Issued: 09/04/2012
• Est. Priority Date: 03/05/2009
• Status: Active Grant

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Takeuchi, Kesatoshi, Nakamura, Kazuyoshi
• Primary Examiner(s): Ro, Bentsu
• Assistant Examiner(s): CARRASQUILLO, JORGE L
• Application Number:
  US12/701,807
• Publication Number:
  US 20100225261A1
• Time in Patent Office: 939 Days
• Field of Search: 318/811, 318/34, 318/280, 318/400.41, 318/400.02, 318/400.04, 318/490, 318/156.35, 318/400.34, 318/282, 318/266, 318/567, 318/802, 318/716, 318/599, 318/725, 318/254.1, 318/286, 318/376, 310/156.35, 310/266, 310/268, 310/156.32, 310/112, 310/113, 310/156.01, 310/156.33, 310/156.36, 310/269, 310/180, 363/37, 369/59.11
• US Class Current: 318/400.29
• CPC Class Codes: H02P 25/18 with arrangements for switching the windings, e.g. with mechanical switches or relays
• CPC Class Codes: H02P 25/184 wherein the motor speed is changed by switching from a delta to a star, e.g. wye, connection of its windings, or vice versa
• CPC Class Codes: H02P 27/08 with pulse width modulation
• CPC Class Codes: H02P 6/085 in a bridge configuration

Abstract

An energy converter includes magnetic coils of N phases (N is an integer of 3 or more), and a PWM drive circuit for driving the magnetic coils of N phases, wherein the magnetic coil of each phase can be independently controlled by the PWM drive circuit.

Claims

1. An electromechanical apparatus comprising:

magnetic coils of N phases (N is an integer of 3 or more);

magnets;

a PWM drive circuit that drives the magnetic coils of N phases; and

a control unit that controls voltage to be applied to the magnetic coil, wherein

the magnetic coil of each phase can be independently controlled by the PWM drive circuit, and

the control unit applies voltage to the magnetic coil in an excitation interval that is symmetric about a π

/2 phase point when a position at which the polarity of a waveform of induced voltage induced in the magnetic coil due to the movement of the magnets is reversed is defined as a π

phase point, does not apply voltage to the magnetic coil in a non-excitation interval that is symmetric about the π

phase point of the waveform of the induced voltage, and makes the length of the non-excitation interval greater as the electromechanical apparatus rotates at high revolution.