Thyristor starter

Patent metadata

Field	Value
Publication number	US-11469692-B2
Application number	US-201816970533-A
Country	US
Kind code	B2
Filing date	Feb 19, 2018
Priority date	Feb 19, 2018
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

A converter controller configured to control a firing phase of a converter includes an integral element integrating a deviation of DC current from a current command value and generates a voltage command value of output voltage of the converter by performing control calculation of the deviation. In a first mode of performing commutation of an inverter by intermittently setting DC current to zero, the converter controller sets DC current to zero for a predetermined pause time by narrowing a phase control angle simultaneously with a commutation command for the inverter. When the control calculation is resumed immediately after the pause time, the converter controller uses a control amount calculated in control calculation immediately before the pause time as a preset value of the integral element immediately after the pause time.

First claim

The invention claimed is:

1. A thyristor starter configured to start a synchronous machine, comprising:
a converter that converts AC power into DC power;
a DC reactor that smoothes the DC power;
an inverter that converts the DC power applied from the converter through the DC reactor into AC power with a variable frequency and supplies the AC power to the synchronous machine;
a position detector that detects a rotor position of the synchronous machine;
a first controller that controls a firing phase of a thyristor in the inverter, based on a detection signal of the position detector; and
a second controller that controls a firing phase of a thyristor in the converter such that DC current flowing through the DC reactor matches a current command value, based on a detection signal of the position detector, wherein
the thyristor starter accelerates the synchronous machine from a stop state to a predetermined rotation speed by successively performing a first mode of performing commutation of the inverter by intermittently setting the DC current to zero and a second mode of performing commutation of the inverter by induced voltage of the synchronous machine,
the second controller includes
a current controller at least including an integral element integrating a deviation of the DC current from the current command value, the current controller generates a voltage command value of output voltage of the converter by performing control calculation of the deviation, and
a control angle calculator that calculates a phase control angle of a thyristor in the converter, based on the voltage command value,

in the first mode, the control angle calculator sets the DC current to zero for a predetermined pause time by narrowing the phase control angle simultaneously with a commutation command for the inverter, and
in the first mode, when the control calculation is resumed immediately after the pause time, the current controller uses a control amount calculated by the control calculation immediately before the pause time as a preset value of the integral element immediately after the pause time.

2. The thyristor starter according to claim 1 , wherein in the first mode, the current controller uses output of the integral element immediately before the pause time as the preset value of the integral element immediately after the pause time.

3. The thyristor starter according to claim 1 , wherein in the first mode, the current controller uses the voltage command value generated immediately before the pause time as the preset value of the integral element immediately after the pause time.

4. A thyristor starter configured to start a synchronous machine, comprising:
a converter that converts AC power into DC power;
a DC reactor that smoothes the DC power;
an inverter that converts the DC power applied from the converter through the DC reactor into AC power with a variable frequency and supplies the AC power to the synchronous machine;
a position detector that detects a rotor position of the synchronous machine;
a voltage detector that detects DC voltage input to the inverter;
a first controller that controls a firing phase of a thyristor in the inverter, based on a detection signal of the position detector; and
a second controller that controls a firing phase of a thyristor in the converter such that DC current flowing through the DC reactor matches a current command value, based on a detection signal of the position detector, wherein
the thyristor starter accelerates the synchronous machine from a stop state to a predetermined rotation speed by successively performing a first mode of performing commutation of the inverter by intermittently setting the DC current to zero and a second mode of performing commutation of the inverter by induced voltage of the synchronous machine,
the second controller includes
a current controller at least including an integral element integrating a deviation of the DC current from the current command value, the current controller generates a voltage command value of output voltage of the converter by performing control calculation of the deviation, and
a control angle calculator that calculates a phase control angle of a thyristor in the converter, based on the voltage command value,

in the first mode, the control angle calculator sets the DC current to zero for a predetermined pause time by narrowing the phase control angle simultaneously with a commutation command for the inverter, and
in the first mode, when the control calculation is resumed immediately after the pause time, the current controller uses DC voltage detected by the voltage detector immediately before the pause time as a preset value of the integral element immediately after the pause time.

5. The thyristor starter according to claim 4 , wherein
the second controller includes a sample and hold circuit that takes in and holds a detection signal of the voltage detector at timing when a commutation command for the inverter is generated, and
the current controller uses the detection signal held in the sample and hold circuit as the preset value of the integral element immediately after the pause time.

6. A thyristor starter configured to start a synchronous machine, comprising:
a converter that converts AC power into DC power;
a DC reactor that smoothes the DC power;
an inverter that converts the DC power applied from the converter through the DC reactor into AC power with a variable frequency and supplies the AC power to the synchronous machine;
a voltage detector that detects AC voltage supplied from the inverter to the synchronous machine;
a first controller that generates a firing command to be applied to a thyristor in the inverter, based on a detection signal of the voltage detector; and
a second controller that controls a firing phase of a thyristor in the converter such that DC current flowing through the DC reactor matches a current command value, wherein
the thyristor starter accelerates the synchronous machine from a stop state to a predetermined rotation speed by successively performing a first mode of performing commutation of the inverter by intermittently setting the DC current to zero and a second mode of performing commutation of the inverter by induced voltage of the synchronous machine,
the second controller includes
a current controller at least including an integral element integrating a deviation of the DC current from the current command value, the current controller generates a voltage command value of output voltage of the converter by performing control calculation of the deviation, and
a control angle calculator that calculates a phase control angle of a thyristor in the converter, based on the voltage command value,

in the first mode, the control angle calculator sets the DC current to zero for a predetermined pause time by narrowing the phase control angle simultaneously with a commutation command for the inverter, and
in the first mode, the current controller
calculates DC voltage appearing between input terminals of the inverter, based on a detection signal of the voltage detector and the firing command, and
when the control calculation is resumed immediately after the pause time, uses the calculated DC voltage as a preset value of the integral element immediately after the pause time.

7. The thyristor starter according to claim 6 , wherein in the first mode, the current controller calculates DC voltage appearing between input terminals of the inverter immediately after the pause time, based on a detection signal of the voltage detector and the firing command.

8. The thyristor starter according to claim 6 , wherein
the AC voltage is three phase AC voltage, and
the voltage detector detects at least two line

Assignees

• Toshiba Mitsubishi Elec Ind

Inventors

• Kawaguchi Hironori
• Ogino Hiroshi
• Matsumoto Yasuaki
• Ando Akinobu

Classifications

• H02P27/06 Primary

  using DC to AC converters or inverters (H02P27/05 takes precedence) · CPC title

• H02M7/12

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title

• H02P6/20

  Arrangements for starting (H02P6/08 takes precedence) · CPC title

• H02P2201/13

  DC-link of current link type, e.g. typically for thyristor bridges, having an inductor in series with rectifier · CPC title

• H02M7/525

  with automatic control of output waveform or frequency (H02M7/517 - H02M7/523 take precedence) · CPC title