EP0074752A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Power conversion circuit
Assignee: Cambio Ragione Sociale graseby Controls Ltd
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Filing: 1982-08-31
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Granted: —
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Expires: 2002-08-31
Abstract
Abstract This invention is an arrangement for driving a multi-phase switched reluctance motor from a two-point d.v. supply (11) in which capacitors (12) and (13) are provided across the supply with their common point (14) constituting a third power supply point. The load windings W i , W 3 , W 5 and W 2 , W 4 , W 6 are connected in two different load circuits connected across the different capacitors, and arrangements including diodes D 1 -D 6 are provided for enabling a winding to return energy to the supply when it is not being used to provide driving torque. In order to prevent the voltage of the third point wandering because the currents in the two load circuits are not the same, voltage metering means (M 3 , M 4 or M 5 , or N 1 , N 2 ) are provided, and they tend to compensate for any variation in the potential of the common point. Control means (21) can control the distribution of current between the various load windings by appropriate control of semi- conductor switches in the various load circuits.
Inventors
- 👤 William Frederick Ray
- 👤 Rex Mountford Davis
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 23:52
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/525; H02M7/5152; H02M7/5155; H02P; H02P25/00; H02P25/02; H02P25/08; H02P25/092; H02P25/0925; H02M7/4811
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
129 words
A Power conversion circuit comprising a direct voltage source having two capacitors (preferably equal capacitors) connected across it in series, two load circuits each comprising one or more loads, (for example the phase windings of a multi-phase switched reluctance motor), the loads in one load circuit being connected to the common point of the capacitors and to one side of the direct voltage source through individual controlled semi-conductor switches, and the loads in the other load circuit being connected between the said common point and the other side of the direct voltage source through individual controlled semi-conductor switches, and control means arranged to control the semi- conductor switches, and means responsive to the potential of the said common point which tend to maintain that potential at a desired value.
Claim 2
Dependent Claim
129 words
A Power conversion circuit comprising a direct voltage source having two capacitors (preferably equal capacitors) connected across it in series, two load circuits each comprising one or more loads, (for example the phase windings of a multi-phase switched reluctance motor), the loads in one load circuit being connected to the common point of the capacitors and to one side of the direct voltage source through individual controlled semi-conductor switches, and the loads in the other load circuit being connected between the said common point and the other side of the direct voltage source through individual controlled semi-conductor switches, and control means arranged to control the semi- conductor switches, and means responsive to the potential of the said common point which tend to maintain that potential at a desired value.
Claim 3
Dependent Claim
29 words
A circuit as claimed in Claim 1 including means responsive to the current in each of one or more loads arranged to control the semi-conductor switch for that load.
Claim 4
Dependent Claim
28 words
A circuit as claimed in Claim 2 in which the switches are controlled to maintain that currents in the loads between respective set.levels, which levels may be adjusted.
Claim 5
Dependent Claim
30 words
A circuit as claimed in Claim 2 including means arranged to render the semi-conductor switches conducting at respective controllable frequencies and to render them non-conducting at certain controllable current levels.
Claim 6
Dependent Claim
26 words
A circuit as claimed in Claim 1 including circuits including semi-conductor devices enabling each load to return energy to one or other of the said capacitors.
Claim 7
Dependent Claim
43 words
A circuit as claimed in any preceding claim, in which the control means is arranged in response to any difference between the potential of the said common point and a reference potential to control the semi-conductor switches to tend to reduce the said-difference.
Claim 8
Dependent Claim
90 words
A circuit as claimed in any of the preceding claims including two separate means, one responsive to the total current in each of the load circuits, the control means being arranged to control the semi- conductor switches to tend to cause the outputs of the two separate means to be equal, and/or in response to the outputs of the said separate means to control the semi-conductor switches to tend to cause the average total current in both load circuits together to correspond to the total power requirement of the load.
Claim 9
Dependent Claim
37 words
A circuit as claimed in Claim 7 in which each of the two separate means comprises a magnetic core linking its load circuit and means for delivering an output dependent upon the flux density in the core.
Claim 10
Dependent Claim
37 words
A circuit as claimed in Claim 8 including on each core a bias winding arranged to produce a bias flux dependent upon the different in potential between the said common point and one side of the supply.
Claim 11
Dependent Claim
38 words
A circuit as claimed in any preceding claim in which the control means is arranged to control the semi-conductor switches to set the current in one load at a value corresponding to the power requirement of that load.
Claim 12
Dependent Claim
47 words
ll. A circuit as claimed in any preceding claim in which the control means is arranged to control the instants of firing and commutating the semi-conductor switches so that the numbers of rises and falls of current per second in the two load circuits are the same.
References Cited (Backward Citations)
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