Control Method and Device for Circuit with a Bridge Arm of a Switch

• US 20180041109A1
• Filed: 08/01/2017
• Published: 02/08/2018
• Est. Priority Date: 08/08/2016
• Status: Active Grant

• Current Assignee: Vertiv Tech Co., Ltd. (Vertiv Holdings Co.)
• Original Assignee: Emerson Network Power Company Limited (Emerson Electric Company)
• Inventors: XU, Fubin, HUANG, Hai, BING, Yang
• Granted Patent: US 10,601,303 B2
• Time in Patent Office: Days
• CPC Class Codes: H02M 1/0048 Circuits or arrangements for reducing losses using snubbers H02M1/34
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 1/083 for the ignition at the zero crossing of the voltage or the current
• CPC Class Codes: H02M 1/088 for the simultaneous control of series or parallel connected semiconductor devices
• CPC Class Codes: H02M 1/342 Active non-dissipative snubbers
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H02M 7/487 Neutral point clamped inverters
• CPC Class Codes: H02M 7/53871 with automatic control of output voltage or current
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The present invention discloses a control method and device for a circuit with a bridge arm of a switch. The soft switching converter comprises at least two bridge arms of the switch, and an auxiliary switch assisting in switching of a main switch of the bridge arm of the switch. The control method comprises the steps of: S1. after controlling the auxiliary switch to be turned on for a first period of time, controlling main switches set at the same position of individual bridge arms of the switch to be simultaneously turned on; S2. after a second period of time following a time when the main switches set at the same position of individual bridge arms of the switch are simultaneously turned on, turning off the auxiliary switch. The present invention can reduce system loss and noise, so as to improve efficiency.

Claims

1. A control method for a circuit with bridge arm of a switch, wherein the circuit comprises at least two bridge arms of the switch and an auxiliary switch assisting in switching of a main switch in the bridge arm of the switch, characterized in that the control method comprises steps of:

S1. after controlling the auxiliary switch to be turned on for a first period of time, controlling main switches set at a same position of individual bridge arms of the switch to be simultaneously turned on;

S2. after a second period of time following a time when the main switches set at the same position of individual bridge arms of the switch are simultaneously turned on, turning off the auxiliary switch.

2. The control method according to claim 1, characterized in that

in the step S1, at a time when current is completely transferred from a main switch circuit comprising the at least two bridge arms of the switch in the circuit to an auxiliary switch circuit comprising the auxiliary switch in the circuit, the main switches set at the same position of individual bridge arms of the switch are controlled to be simultaneously turned on;

in the step S2, at a time when current is completely transferred from the auxiliary switch circuit to the main switch circuit, the auxiliary switch is turned off.

3. The control method according to claim 2, characterized in that

the bridge arm of the switch is NPC bridge arm of a switch.

4. The control method according to claim 3, characterized in that

in the step S1, the main switches at the same position of individual bridge arms of the switch which are connected with a bus are controlled to be simultaneously turned on.

5. The control method according to claim 1, characterized in that

control signals of the main switch of the bridge arm of the switch and the auxiliary switch are formed by modulating a carrier signal;

prior to the step S1, the control method further comprises a step of;

detecting whether or not an effective edge of the carrier signal appears, and if YES, starting to perform the step S1.

6. The control method according to claim 5, characterized in that

the carrier signal is right-angled sawtooth wave, the effective edge is a rising edge of the right-angled sawtooth wave.

7. The control method according to claim 1, characterized in that

the circuit is a soft switching converter.

8. The control method according to claim 1, characterized in that

the circuit is an AC/DC circuit or a DC/AC circuit.

9. A control device for a circuit with bridge arm of a switch, wherein the circuit comprises at least two bridge arms of the switch and an auxiliary switch assisting in switching of a main switch of the bridge arm of the switch, characterized in that the control device comprises:

a first control unit for, after controlling the auxiliary switch to be turned on for a first period of time, controlling main switches set at a same position of individual bridge arms of the switch to be simultaneously turned on;

a second control unit for, after a second period of time following a time when the main switches set at the same position of individual bridge arms of the switch are simultaneously turned on, turning off the auxiliary switch.

10. The control device according to claim 9, characterized in that

the first control unit is used for, at a time when current is completely transferred from a main switch circuit comprising the at least two bridge arms of the switch in the circuit to an auxiliary switch circuit comprising the auxiliary switch in the circuit, controlling the main switches set at the same position of individual bridge arms of the switch to be simultaneously turned on;

the second control unit for, at a time when current is completely transferred from the auxiliary switch circuit to the main switch circuit, turning off the auxiliary switch.