GB1363036A – Changing the frequency of a polyphase alternating current supply and apparatus therefor
– Google Patents
GB1363036A – Changing the frequency of a polyphase alternating current supply and apparatus therefor
– Google Patents
Changing the frequency of a polyphase alternating current supply and apparatus therefor
Info
Publication number
GB1363036A
GB1363036A
GB4354072A
GB4354072A
GB1363036A
GB 1363036 A
GB1363036 A
GB 1363036A
GB 4354072 A
GB4354072 A
GB 4354072A
GB 4354072 A
GB4354072 A
GB 4354072A
GB 1363036 A
GB1363036 A
GB 1363036A
Authority
GB
United Kingdom
Prior art keywords
output
frequency
gates
zero
current
Prior art date
1971-10-07
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB4354072A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TIME MODULATION Pty Ltd
Original Assignee
TIME MODULATION Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1971-10-07
Filing date
1972-09-20
Publication date
1974-08-14
1972-09-20
Application filed by TIME MODULATION Pty Ltd
filed
Critical
TIME MODULATION Pty Ltd
1974-08-14
Publication of GB1363036A
publication
Critical
patent/GB1363036A/en
Status
Expired
legal-status
Critical
Current
Links
Espacenet
Global Dossier
Discuss
Classifications
H—ELECTRICITY
H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
H02M5/02—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc
H02M5/04—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters
H02M5/22—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02M5/25—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means
H02M5/27—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means for conversion of frequency
H02M5/271—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into dc by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a thyratron or thyristor type requiring extinguishing means for conversion of frequency from a three phase input voltage
Abstract
1363036 Frequency changing; control of AC motors TIME MODULATION (PTY) Ltd 20 Sept 1972 [7 Oct 1971] 43540/72 Headings H2F and H2J A frequency changer comprises matrices of thyristors or Triacs connected between each input line of a three-phase supply 14 and opposite ends of output circuits A, B, C, the matrices being made available for triggering in a predetermined cyclic sequence and triggered when the input current as monitored at 28 passes through zero. As described, each matrix A, B, C consists of a Triac or anti-parallel pair of thyristors connected between each input line and one end of the winding of a synchronous or asynchronous motor the speed of which is to be controlled. The output frequency is controlled by a master oscillator 26 variable between 0 and 300 Hz. Pulses from 26 are distributed to AND gates 18 by means of a ring counter 22. The AND gates 18 are inhibited by means of a latch 20 set by each pulse from the oscillator 26 and cleared by each passage through zero of the input current as detected at 28 after an adjustable delay 32À2 sufficient to allow the main thyristors to turn off and adjustable so as to vary the output voltage. Pulses passing AND gates 18 are fed to a decoding matrix 24 and gate the output of a free-running multivibrator (Fig. 9, not shown) to the trigger circuit of the appropriate thyristor or Triac. Monitoring current zeros.-As shown in Fig. 11, the current of each supply line 14 develops a small voltage across a pair of anti-parallel power diodes 28-1 which voltage is passed by a transistor amplifier to a further free-running multivibrator 28À2 so that the operation of the multivibrator is inhibited except during passages through zero of the input current. At such times, the output is rectified and provides a control voltage at 28À3 which is passed via a gate (Fig. 12, not shown) together with the output of the other two current detectors so as to clear the latch 20 after the delay imposed at 32À2. Forced commutation circuit.-Fig. 13 shows a transistor 30À 1 across a diode bridge connected in one of the input lines. Each pulse from the master oscillator gates on a further free-running multivibrator 30À2 which provides output signals at X1, X2 to turn off transistor 30À1 thus creating a zero in that input line. Transistor 30À 1 may be replaced by a thyristor, force-commutated by reactors and capacitors. Controlling A.C. motors.-The Specification describes how the speed and’direction of motor ABC may be varied by control of frequency of oscillator 26 and suggests that some of the steps in the sequence provided by blocks 22, 18, 24 may be missed during certain speed ranges.
GB4354072A
1971-10-07
1972-09-20
Changing the frequency of a polyphase alternating current supply and apparatus therefor
Expired
GB1363036A
(en)
Applications Claiming Priority (1)
Application Number
Priority Date
Filing Date
Title
ZA716729A
ZA716729B
(en)
1971-10-07
1971-10-07
Changing the frequency of a polyphase alternating current supply and apparatus therefor
Publications (1)
Publication Number
Publication Date
GB1363036A
true
GB1363036A
(en)
1974-08-14
Family
ID=25564000
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
GB4354072A
Expired
GB1363036A
(en)
1971-10-07
1972-09-20
Changing the frequency of a polyphase alternating current supply and apparatus therefor
Country Status (7)
Country
Link
US
(1)
US3816808A
(en)
JP
(1)
JPS4947846A
(en)
AU
(1)
AU4692972A
(en)
DE
(1)
DE2247427A1
(en)
GB
(1)
GB1363036A
(en)
IT
(1)
IT968502B
(en)
ZA
(1)
ZA716729B
(en)
Families Citing this family (5)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US3946293A
(en)
*
1974-09-13
1976-03-23
Conco Inc.
Thyristor control system
US4078192A
(en)
*
1976-06-24
1978-03-07
Pertec Computer Corporation
Synthesizer for multiphase waveforms
FR2449360A1
(en)
*
1979-02-13
1980-09-12
Telemecanique Electrique
THYRISTOR THREE-PHASE MOUNTING CONTROL DEVICE
US4468725A
(en)
*
1982-06-18
1984-08-28
Texas Instruments Incorporated
Direct AC converter for converting a balanced AC polyphase input to an output voltage
US4713744A
(en)
*
1986-10-28
1987-12-15
Torcon Products, Inc.
Fractional frequency converter using zero switching of input frequency halfwaves
Family Cites Families (4)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
GB1270136A
(en)
*
1968-08-15
1972-04-12
Nicholas Charl De Villiers
Polyphase alternating current frequency changer
GB1309641A
(en)
*
1969-10-24
1973-03-14
Secr Defence
Cycloconverters
US3703672A
(en)
*
1970-05-05
1972-11-21
Nat Res Dev
Three-phase induction-motor, speed-changing method and control circuit
US3686558A
(en)
*
1971-01-04
1972-08-22
Ajax Magnethermic Corp
Control for frequency converters
1971
1971-10-07
ZA
ZA716729A
patent/ZA716729B/en
unknown
1972
1972-09-20
US
US00290470A
patent/US3816808A/en
not_active
Expired – Lifetime
1972-09-20
GB
GB4354072A
patent/GB1363036A/en
not_active
Expired
1972-09-21
AU
AU46929/72A
patent/AU4692972A/en
not_active
Expired
1972-09-27
DE
DE19722247427
patent/DE2247427A1/en
active
Pending
1972-09-30
IT
IT29939/72A
patent/IT968502B/en
active
1972-10-04
JP
JP47099105A
patent/JPS4947846A/ja
active
Pending
Also Published As
Publication number
Publication date
ZA716729B
(en)
1973-02-28
AU4692972A
(en)
1974-03-28
JPS4947846A
(en)
1974-05-09
US3816808A
(en)
1974-06-11
IT968502B
(en)
1974-03-20
DE2247427A1
(en)
1973-04-12
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Legal Events
Date
Code
Title
Description
1974-12-27
PS
Patent sealed [section 19, patents act 1949]
1977-04-21
PLNP
Patent lapsed through nonpayment of renewal fees
