Patent US3694730A successfully refreshed from Google Patents.
US3694730A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thyristor c.c. switch
Assignee: Emerson Electric Co
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Filing: 1971-05-03
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Granted: 1972-09-26
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Expires: 1991-05-03
Abstract
Abstract An inverter commutation circuit has a thyristor (SCR) line switch interposed in one side of a D.C. line. Opening the line switch provides commutation for the inverter. The line switch is opened by discharging a capacitor through a diode connected in parallel with the switch. Load current is transferred to a diode coasting path while the line switch is open. The line switch is closed and the capacitor is charged to commutation voltage before the switch is reopened. Frequency control is provided by the cyclic repetition of the line switch and corresponding inverter operation. The line switch may be applied in a variety of inverter systems. The circuit provides means for a method of static inverter commutation by interruption of the supply line.
Inventors
- 👤 Richard G Hoft
- 👤 Tsuneo Kume
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:18
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/06; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/5152
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
329 words
A D.C. switch circuit comprising: a first electrical conductor for electrically connecting said switch to a negative source of D.C. voltage; a first electrical switch of a silicon controlled rectifier type having an anode and a cathode corresponding to an input side and an output side connected in series with said first conductor; means for placing said first electrical switch in an on position for current flow in said first electrical conductor electrically connected to said first switch; means for placing said first electrical switch in an off position for preventing current flow in said first electrical conductor electrically connected to said first electrical switch, said means comprising a series circuit having a commutating capacitor, a first inductor, a second switch, and a diode electrically connected across said input and output sides of said silicon controlled rectifier switch whereby closing said second switch discharges said commutating capacitor across said diode, reversing the voltage across and commutating said silicon controlled rectifier; a coasting path electrical conductor electrically connected to said output side of said first electrical switch for connecting said output side to a static inverter circuit; a second electrical conductor electrically connected to a positive side of said D.C. source voltage; a circuit comprising a third electrical switch, a second inductor connected in series with said third switch, said third switch and second inductor being electrically connected between said second electrical connector and a connection node in said series circuit of said off positioning means intermediate said first inductor and said commutating capacitor, wherein closing said third switch recharges said commutating capacitor, said second inductor comprising a primary winding for a transformer having a secondarY winding with a first side electrically connected to said first electrical conductor on the cathode side of said first electrical switch, and a diode electrically connected between a second side of said secondary winding and said second electrical conductor, said secondary winding and diode circuit comprising a first voltage clamp for said commutating capacitor.
Claim 2
Dependent Claim
329 words
A D.C. switch circuit comprising: a first electrical conductor for electrically connecting said switch to a negative source of D.C. voltage; a first electrical switch of a silicon controlled rectifier type having an anode and a cathode corresponding to an input side and an output side connected in series with said first conductor; means for placing said first electrical switch in an on position for current flow in said first electrical conductor electrically connected to said first switch; means for placing said first electrical switch in an off position for preventing current flow in said first electrical conductor electrically connected to said first electrical switch, said means comprising a series circuit having a commutating capacitor, a first inductor, a second switch, and a diode electrically connected across said input and output sides of said silicon controlled rectifier switch whereby closing said second switch discharges said commutating capacitor across said diode, reversing the voltage across and commutating said silicon controlled rectifier; a coasting path electrical conductor electrically connected to said output side of said first electrical switch for connecting said output side to a static inverter circuit; a second electrical conductor electrically connected to a positive side of said D.C. source voltage; a circuit comprising a third electrical switch, a second inductor connected in series with said third switch, said third switch and second inductor being electrically connected between said second electrical connector and a connection node in said series circuit of said off positioning means intermediate said first inductor and said commutating capacitor, wherein closing said third switch recharges said commutating capacitor, said second inductor comprising a primary winding for a transformer having a secondarY winding with a first side electrically connected to said first electrical conductor on the cathode side of said first electrical switch, and a diode electrically connected between a second side of said secondary winding and said second electrical conductor, said secondary winding and diode circuit comprising a first voltage clamp for said commutating capacitor.
Claim 3
Dependent Claim
50 words
The D.C. switch circuit of claim 1 wherein a fourth electrical switch is electrically connected from said anode side of said first switch through a third inductor to said connection node intermediate said first inductor and said commutating capacitor, wherein closing said fourth switch acts to recharge said commutating capacitor.
Claim 4
Dependent Claim
76 words
The D.C. switch circuit of claim 2 wherein aid third inductor comprises a primary winding for a second transformer having a secondary winding with a first side electrically connected to said first electrical conductor on the anode side of said first electrical switch, and a diode electrically connected between a second side of said secondary winding and said second electrical conductor, said secondary winding and diode circuit comprising a second voltage clamp for said commutating capacitor.
Claim 5
Dependent Claim
139 words
A D.C. line switch having two input terminals and three output terminals comprising: a first electrical conductor connected between the first input terminal and the first output terminal for electrically connecting a positive side of D.C. source voltage to said switch; a second electrical conductor connected between the second input terminal and the second output terminal for electrically connecting a negative side of said D.C. source voltage to said switch and said second input terminal; an electrical switch having input and output sides electrically interposed in series in said second electrical conductor; a third electrical conductor connected between a connection node on said output side of said electrical switch to the third output terminal; means for opening said line switch electrically connected to said line switch; and means for closing said line switch electrically connected to said line switch.
Claim 6
Dependent Claim
139 words
A D.C. line switch having two input terminals and three output terminals comprising: a first electrical conductor connected between the first input terminal and the first output terminal for electrically connecting a positive side of D.C. source voltage to said switch; a second electrical conductor connected between the second input terminal and the second output terminal for electrically connecting a negative side of said D.C. source voltage to said switch and said second input terminal; an electrical switch having input and output sides electrically interposed in series in said second electrical conductor; a third electrical conductor connected between a connection node on said output side of said electrical switch to the third output terminal; means for opening said line switch electrically connected to said line switch; and means for closing said line switch electrically connected to said line switch.
Claim 7
Dependent Claim
15 words
The D.C. line switch of claim 4 wherein said switch is a silicon controlled rectifier.
Claim 8
Dependent Claim
163 words
A D.C. line switch having two input terminals and three output terminals comprising: a first electrical conductor connected between the first input terminal and the first output terminal for electrically connecting the positive side of D.C. source voltage to said switch a second electrical conductor connected between the second input terminal and the second output terminal for electrically connecting a negative side of said D.C. source voltage to said switch and said second input terminal; an electrical switch having an input and output sides electrically interposed in series in said second electrical conductor; a third electrical conductor connected between a connection node on said output side of said electrical switch to the third input terminal; means for opening said line switch including a commutating capacitor electrically connected to said line switch; means for recharging said commutating capacitor; means for providing a first voltage clamp during recharging of said commutating capacitor; and means for closing said line switch electrically connected to said line switch.
Claim 9
Dependent Claim
163 words
A D.C. line switch having two input terminals and three output terminals comprising: a first electrical conductor connected between the first input terminal and the first output terminal for electrically connecting the positive side of D.C. source voltage to said switch a second electrical conductor connected between the second input terminal and the second output terminal for electrically connecting a negative side of said D.C. source voltage to said switch and said second input terminal; an electrical switch having an input and output sides electrically interposed in series in said second electrical conductor; a third electrical conductor connected between a connection node on said output side of said electrical switch to the third input terminal; means for opening said line switch including a commutating capacitor electrically connected to said line switch; means for recharging said commutating capacitor; means for providing a first voltage clamp during recharging of said commutating capacitor; and means for closing said line switch electrically connected to said line switch.
Claim 10
Dependent Claim
22 words
The line switch of claim 6 further characterized by means for providing a second voltage clamp during recharging of said commutating capacitor.
Claim 11
Dependent Claim
172 words
A D.C. line switch for interrupting a source of D.C. voltage to a load comprising: an SCR having an anode and a cathode electrically connected to a first side of said D.C. voltage; a commutation circuit electrically connected to said SCR including a commutating capacitor, a first inductor, and a first electrical switch connected in series between said anode and said cathode of said SCR and a commutating diode of opposite polarity connected in parallel betweeN said anode and said cathode of said SCR; a coasting path conductor electrically connected from said cathode of said SCR to said load; means for recharging said commutating capacitor comprising a second electrical switch and a second inductor in series with said last-mentioned switch electrically connected between a second side of said D.C. voltage and a connection node between said commutating capacitor and said first inductor; and at least one voltage clamp electrically connected to said means for recharging said commutating capacitor so as to restrict voltage changes of said capacitor during charging of said capacitor.
Claim 12
Dependent Claim
172 words
A D.C. line switch for interrupting a source of D.C. voltage to a load comprising: an SCR having an anode and a cathode electrically connected to a first side of said D.C. voltage; a commutation circuit electrically connected to said SCR including a commutating capacitor, a first inductor, and a first electrical switch connected in series between said anode and said cathode of said SCR and a commutating diode of opposite polarity connected in parallel betweeN said anode and said cathode of said SCR; a coasting path conductor electrically connected from said cathode of said SCR to said load; means for recharging said commutating capacitor comprising a second electrical switch and a second inductor in series with said last-mentioned switch electrically connected between a second side of said D.C. voltage and a connection node between said commutating capacitor and said first inductor; and at least one voltage clamp electrically connected to said means for recharging said commutating capacitor so as to restrict voltage changes of said capacitor during charging of said capacitor.
Claim 13
Dependent Claim
77 words
The D.C. line switch of claim 8 wherein said second inductor comprises a first transformer, a primary winding of said first transformer comprising a said second series inductor and a secondary winding of said first transformer being electrically connected from the cathode of said SCR to said second side of said D.C. voltage through a series diode, said secondary winding inductor and said series diode comprising said first voltage clamp during charging periods of said commutating capacitor.
Claim 14
Dependent Claim
74 words
The D.C. line switch of claim 9 further characterized by a third electrical switch and a third inductor, a first side of said third electrical switch being connected to the anode side of said SCR and a second side of said third switch being connected to a first side of said third inductor, the second side of said third inductor being connected to said connection node between said commutating capacitor and said first inductor.
Claim 15
Dependent Claim
95 words
The D.C. switch of claim 10 wherein said third inductor comprises a second transformer having a primary winding and a secondary winding, said primary winding of the last mentioned transformer being connected between said connection node and said third switch and said secondary winding of the last mentioned transformer being connected between said coasting path conductor and the anode of a diode, the cathode of said diode being connected to said second side of said D.C. voltage, said secondary winding and said diode forming a second voltage clamp during charging periods of said commutating capacitor.
Claim 16
Dependent Claim
154 words
The D.C. switch of claim 8 wherein said means for recharging said commutating capacitor further comprises a second SCR having an anode and a cathode and a transformer having a primary winding and a secondary winding, the anode of said second SCR being connected to the anode of said first SCR and the cathode of said second SCR being connected through said primary winding of said transformer to said connection node between said first inductor and said commutating capacitor, and a clamping diode having an anode and a cathode, the cathode of said clamping diode being connected to said second side of said D.C. voltage and the anode of said clamping diode being connected to a first side of said transformer secondary winding, a second side of said transformer secondary winding being connected to said coasting path conductor, said transformer secondary winding and said clamping diode comprising said voltage clamp for said commutating capacitor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |