US3657634A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inverter circuit
Assignee: Siemens Mobility Ltd
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Filing: 1970-11-03
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Granted: 1972-04-18
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Expires: 1990-11-03
Abstract
Abstract In an inverter circuit including first and second pairs of main controllable rectifier devices connected in a bridge configuration between d.c. supply terminals and a resonant load connected across the bridge, an auxiliary commutation circuit is provided for diverting current, over a number of cycles following starting of the inverter, from the controllable rectifier devices at the instant a controllable rectifier device is to be commutated into the non-conducting condition thereof so as to assist in said commutation. An additional circuit is provided for ''''shocking'''' the load circuit into resonance during start-up. The load circuit provides natural commutation of the pairs of controllable rectifier devices during normal operation and, during starting, triggering pulses are applied to the incoming controllable rectifier devices sufficiently before the voltage zero of the natural resonant load circuit frequency to ensure adequate build-up of current in these incoming devices.
Inventors
- 👤 Robert Henry Eastop
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:03
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/5152
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
161 words
In an inverter circuit including first and second main controllable rectifier means connected between d.c. supply terminals and load terminals for connection to a load circuit, said first and second controllable rectifier means operating to conduct alternately so as to supply current in opposite directions through the load terminals and initiation of conduction of either of said controllable rectifier means being effective, in operation, to cause commutation of the other of said controllable rectifier means into the non-conducting condition, the improvement comprising additional circuit means for initiating resonance in the load circuit and an auxiliary commutation circuit for diverting current, over a number of cycles following starting of the inverter, from the controllable rectifier means at the instant a said controllable rectifier means is to be commutated into the non-conducting condition so as to assist in said commutation, said auxiliary commutation circuit including capacitive and inductive components connected in a resonant L-C circuit, the said inductive component not carrying load current.
Claim 2
Dependent Claim
161 words
In an inverter circuit including first and second main controllable rectifier means connected between d.c. supply terminals and load terminals for connection to a load circuit, said first and second controllable rectifier means operating to conduct alternately so as to supply current in opposite directions through the load terminals and initiation of conduction of either of said controllable rectifier means being effective, in operation, to cause commutation of the other of said controllable rectifier means into the non-conducting condition, the improvement comprising additional circuit means for initiating resonance in the load circuit and an auxiliary commutation circuit for diverting current, over a number of cycles following starting of the inverter, from the controllable rectifier means at the instant a said controllable rectifier means is to be commutated into the non-conducting condition so as to assist in said commutation, said auxiliary commutation circuit including capacitive and inductive components connected in a resonant L-C circuit, the said inductive component not carrying load current.
Claim 3
Dependent Claim
64 words
An inverter circuit as claimed in claim 1 wherein said load circuit provides natural commutation of said first and second controllable rectifier means during normal operation and wherein, during starting, triggering pulses are applied to the incoming controllable rectifier means sufficiently before the voltage zero of the natural resonant load circuit frequency to ensure adequate build-up of current in said incoming controllable rectifier means.
Claim 4
Dependent Claim
24 words
An inverter circuit as claimed in claim 1, the auxiliary commutation circuit including a source of voltage switchable at said instant into said path.
Claim 5
Dependent Claim
22 words
An inverter circuit as claimed in claim 3, the source of voltage being switchable into said path via further controllable semiconductor means.
Claim 6
Dependent Claim
54 words
An inverter circuit as claimed in claim 4 wherein said path includes said inductive and capacitive components, said components including an inductance and a first capacitance, the further controllable rectifier means being such as to alternately connect said capacitance in opposite senses into said path with respect to the d.c. lines of the inverter.
Claim 7
Dependent Claim
23 words
An inverter circuit as claimed in claim 5, said source of voltage comprising a second capacitance and charging means for charging said capacitance.
Claim 8
Dependent Claim
67 words
An inverter circuit as claimed in claim 6 the charging means and the values of said first and second capacitances being so chosen as to enable progressive charging of the second capacitor towards a value opposite to that afforded by the charging means such that the inverter circuit tends to revert to natural commutation by virtue of the output voltage following a number of cycles after starting.
Claim 9
Dependent Claim
36 words
An inverter circuit as claimed in claim 2 further comprising a diode for, when conducting, causing switching of said source of voltage, and generating means for generating a current pulse in said diode at said instant.
Claim 10
Dependent Claim
25 words
An inverter circuit as claimed in claim 8, said diode being connected across the d.c. lines of said inverter via a further oppositely poled diode.
Claim 11
Dependent Claim
28 words
An inverter as claimed in claim 8, the generating means including an inductance and capacitance and further switching means for producing a unidirectional current pulse in the diode.
Claim 12
Dependent Claim
68 words
An inverter circuit as claimed in claim 10, the further switching means comprising controllable semiconductor rectifiers in a bridge configuration, a capacitance connected in the ''''a.c.'''' path of the bridge configuration, an inductance and a further source, and means for rendering the controllable semiconductor rectifier means conducting selectively to alternately transmit current via the L-C. circuit provided by the capacitance and inductance in alternate directions through the capacitance.
Claim 13
Dependent Claim
22 words
An inverter circuit as claimed in claim 1, the firsT and second controllable rectifier means being arranged in a bridge circuit configuration.
Claim 14
Dependent Claim
39 words
An inverter circuit as claimed in claim 1 wherein said additional circuit means is connected across the d.c. lines of the inverter and operable prior to starting of the inverter to establish a predetermined current from a d.c. supply.
Claim 15
Dependent Claim
27 words
An inverter circuit as claimed in claim 13, the additional circuit means including a semiconductor controllable rectifier, a capacitance and a current sensing device connected in series.
Claim 16
Dependent Claim
34 words
An inverter circuit as claimed in claim 14, further comprising means for initiating triggering of the main controllable rectifier means on starting in response to a predetermined current being sensed by said sensing means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-04-18 | 1975-10-18 | 1976-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-18 | 1979-10-18 | 1980-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-18 | 1983-10-18 | 1984-04-18 | $7700.00 | Window Closed / Lapsed |