CN110667866B

CN110667866B - External power supply voltage, overload, frequency and open-phase protection structure of bus bar power controller

Info

Publication number: CN110667866B
Application number: CN201810719258.5A
Authority: CN
Inventors: 万波
Original assignee: Shanghai Aviation Electric Co Ltd
Current assignee: Shanghai Aviation Electric Co Ltd
Priority date: 2018-07-03
Filing date: 2018-07-03
Publication date: 2022-09-06
Anticipated expiration: 2038-07-03
Also published as: CN110667866A

Abstract

The invention discloses an external power supply voltage protection structure of a bus bar power controller, wherein voltage protection functions comprise Overvoltage (OV) protection, Undervoltage (UV) protection and Phase Sequence (PS) protection, and a BPCU can implement protection when detecting that an external power supply is too high, too low or a phase sequence is wrong. The invention has the advantage that the fault condition can be reset under the condition of meeting the corresponding condition.

Description

External power supply voltage, overload, frequency and open-phase protection structure of bus bar power controller

Technical Field

The invention relates to an external power supply voltage, overload, frequency and open-phase protection structure of a bus bar power controller.

Background

The Bus Power Control Unit (BPCU) has two functions, one is to realize load-oriented Power transmission through Control of the aircraft grid Power switch under normal conditions, and the other is to provide protection for the distribution Bus and the Power elements. Wherein external supply voltage protection is a basic protection function of the BPCU.

The conventional aircraft power system is relatively simple in configuration, and the control logic of the BPCU is relatively simple. In a multi-power architecture, the BPCU external power supply voltage protection control logic is set according to a new power supply system configuration.

Disclosure of Invention

The invention provides an external power supply voltage, overload, frequency and open-phase protection structure of a single-channel multi-electric-plane bus bar power controller.

In order to realize the purpose, the technical scheme of the invention is as follows: the external power voltage protection structure of bus bar power controller is characterized by comprising,

the main generator GEN L is connected with the first end of the circuit breaker L GCB, and the second end of the circuit breaker L GCB is connected with the Bus bar L235 VAC Bus;

the main generator GEN R is connected with the first end of the breaker R GCB, and the second end of the breaker R GCB is connected with the Bus bar R235 VAC Bus;

the auxiliary generator APU GEN is connected with the first end of the circuit breaker APB, the Bus bar L235 VAC Bus is connected with the first end of the contactor L BTB, the Bus bar R235 VAC Bus is connected with the first end of the contactor R BTB, and the second end of the contactor APB is connected with the second end of the contactor L BTB and the second end of the contactor R BTB respectively;

the Bus bar L235 VAC Bus is connected with a first end of a contactor L ATUC, a second end of the contactor L ATUC is connected with an electric energy conversion device L ATU, the electric energy conversion device L ATU is connected with a first end of a contactor L BSB, and a second end of the contactor L BSB is connected with the Bus bar L115 VAC Bus;

the Bus bar R235 VAC Bus is connected with a first end of a contactor R ATUC, a second end of the contactor R ATUC is connected with an electric energy conversion device R ATU, the electric energy conversion device R ATU is connected with a first end of a contactor R BSB, and a second end of the contactor R BSB is connected with the Bus bar R115 VAC Bus;

a ground power supply L FWD EP is connected with a first end of a contactor L EPC, and a second end of the contactor L EPC is connected with a first end of a contactor L BSB;

a ground power supply R FWD EP is connected with a first end of a contactor R EPC, and a second end of the contactor R EPC is connected with a first end of a contactor R BSB;

the Bus bar L235 VAC Bus is connected with the first end of the contactor LacT, the second end of the contactor LacT is connected with the first end of the contactor RacT, and the second end of the contactor RacT is connected with the Bus bar R235 VAC Bus;

the second end of the contactor L ATUC is connected with the first end of the contactor L TRU Rly, the second end of the contactor L TRU Rly is connected with the power conversion device TRU L, and the power conversion device TRU L is connected with the Bus bar L28 VDC Bus;

the second end of the contactor R ATUC is connected with the first end of the contactor R TRU Rly, the second end of the contactor R TRU Rly is connected with the power conversion device TRU R, and the power conversion device TRU R is connected with the Bus bar R28 VDC Bus;

bus bar L28 VDC Bus is connected to a first terminal of contact LdcT, a second terminal of contact LdcT is connected to a first terminal of contact RdcT, a second terminal of contact RdcT is connected to Bus bar R28 VDC Bus;

the second end of the contactor L ATUC is connected with the first end of the contactor E1 TRU ISO Rly, the second end of the contactor E1 TRU ISO Rly is respectively connected with the first ends of a power conversion device TRU 1 and a contactor E1 TRU Rly, the power conversion device TRU 1 is further connected with the first end of a Bus bar ESS 128 VDC Bus, the second end of the contactor ESS ISO Rly is connected with a Bus bar ESS 235VAC Bus, the Bus bar ESS 235VAC Bus is connected with a power conversion device TRU 2, and the power conversion device TRU E2 is further connected with the Bus bar ESS 228 VDC Bus;

the generator GEN RAT is connected with a first end of a contactor RCB, and a second end of the contactor RCB is connected with a Bus bar ESS 235VAC Bus;

bus ESS 128 VDC Bus is connected to the first terminal of contact E1T, the second terminal of contact E1T is connected to the first terminal of contact E2T, and the second terminal of contact E2T is connected to Bus ESS 228 VDC Bus;

bus ESS 128 VDC Bus is connected to a first terminal of contactor MBR, and a second terminal of contactor MBR is connected to Bus Hot BB 1;

the bus bar Hot BB2 is connected with a first end of a contactor SPUC, a second end of the contactor SPUC is connected with an SPU, the SPU is connected with a first end of a contactor SPUB, and a second end of the contactor SPUB is connected with an ATRU R;

the Bus bar L235 VAC Bus is connected with a first end of a contactor L ATRUC, a second end of the contactor L ATRUC is connected with an ATRU L, and the ATRU L is connected with the Bus bar L270 VDC Bus;

the Bus bar R235 VAC Bus is connected with the first end of the contactor R ATRUC, the second end of the contactor R ATRUC is connected with the autotransformer rectifier ATRUR, and the autotransformer rectifier ATRUR is connected with the Bus bar R270 VDC Bus;

an external power supply L AFT EP is connected with a first end of a contactor L AEPC, and a second end of the contactor L AEPC is connected with an autotransformer rectifier ATRU L;

the voltage protection functions include over-voltage (OV) protection, under-voltage (UV) protection, and Phase Sequence (PS) protection.

The power supply of the main generator GEN L and the power supply of the main generator GEN R are both variable frequency generators with rated power of 225kVA and rated voltage of 235 VAC; the auxiliary generator APU GEN is a variable frequency generator with rated power of 200kVA and rated voltage of 235 VAC; the generator GEN RAT is a variable frequency generator with rated power of 50kVA and rated voltage of 235 VAC; rated voltages of the ground power supply L FWD EP, the ground power supply R FWD EP and the third external power supply L AFT EP are 115 VAC; rated power of the ATRU L and the ATRU R is 150kVA, rated capacity of the ATU and the ATU is 60kVA, and rated output current of the TRU L, the TRU R, the TRU E1 and the TRU E2 is 240A; the storage battery Main BAT and the storage battery APU BAT are both storage batteries with rated voltage of 28VDC and capacity of 75 Ah.

An overload protection structure for external power supply of bus power controller is characterized in that it comprises,

the GEN R of the main generator is connected with the first end of the circuit breaker R GCB, and the second end of the circuit breaker R GCB is connected with the Bus bar R235 VAC Bus;

the Bus bar L28 VDC Bus is connected with a first end of a contactor LdcT, a second end of the contactor LdcT is connected with a first end of a contactor RdcT, and a second end of the contactor RdcT is connected with the Bus bar R28 VDC Bus;

the Bus ESS 128 VDC Bus is connected to the first terminal of contact E1T, the second terminal of contact E1T is connected to the first terminal of contact E2T, and the second terminal of contact E2T is connected to the Bus ESS 228 VDC Bus;

the Bus bar L235 VAC Bus is connected with a first end of a contactor L ATRUC, a second end of the contactor L ATRUC is connected with an autotransformer rectifier ATRU L, and the autotransformer rectifier ATRU L is connected with the Bus bar L270 VDC Bus;

and the bus bar power controller L/R BPCU is used for collecting three-phase current of the ground power supply L/R FWD EP, wherein a collecting point is positioned on a feeder line of the L/R EPC contactor close to the ground power supply vehicle, and the collecting point is positioned at A, B, C three-phase current of the L/R FWD EP.

An external power frequency protection structure of a bus power controller includes,

the Bus bar R235 VAC Bus is connected with the first end of the contactor R ATUC, the second end of the contactor R ATUC is connected with the electric energy conversion device R ATU, the electric energy conversion device R ATU is connected with the first end of the contactor R BSB, and the second end of the contactor R BSB is connected with the Bus bar R115 VAC Bus;

the Bus bar R235 VAC Bus is connected with the first end of the contactor R ATRUC, the second end of the contactor R ATRUC is connected with the autotransformer rectifier ATRU R, and the autotransformer rectifier ATRU R is connected with the Bus bar R270 VDC Bus;

the L/R BPCU collects the frequency corresponding to the L/R FWD EP A phase, and the collection point is located at the end of the L/R EPC close to the ground power supply side.

When the collected frequency is larger than or equal to 410Hz, the over-frequency (OF) protection OF the BPCU acts, and the L/R FWD EPC is disconnected and locked.

When the L/R FWD EP UV condition is met, L/R FWD EP OF protection is inhibited.

When the L/R FWD EP A phase frequency drops below 409Hz, the L/R FWD EP OF trip protection can be reset by one OF the following three standard methods:

1) pressing an L/R FWD EXT PWR switch on a control panel of the cockpit;

2) the L/R FWD EP plug on the corresponding socket is pulled out and plugged again;

3) the corresponding BPCU is unplugged and powered up again.

When the collected frequency is less than or equal to 390Hz, the under-frequency (UF) protection of the BPCU acts, and the L/R FWD EPC is disconnected and locked.

When the L/R FWD EP UV condition is met, L/R FWD EP UF protection is inhibited.

When the L/R FWD EP A phase frequency rises back above 391Hz, the L/R FWD EP UF protection trip can be reset by one of three standard methods:

1) pressing an L/R FWD EXT PWR switch on a cockpit control panel;

2) the L/R FWD EP plug on the corresponding socket is unplugged and plugged again;

3) the corresponding BPCU is unplugged and powered up again.

The phase-loss protection structure of external power source for bus bar power controller comprises,

the main generator GEN L is provided with a generator controller L GCU, the generator controller L GCU is used for sensing voltage and current at the circuit breaker L GCB, and if the reactive power output of the main generator GEN L is lower than a first threshold value, the generator controller L GCU executes continuous unfired power source protection action;

the main generator GEN R has a generator controller rccu for sensing the voltage current at the circuit breaker rcgb, the generator controller rccu performing a continuous unfired power source protection action if the reactive power output of the main generator GEN R is below a second threshold;

the auxiliary generator APU GEN is provided with a generator controller A GCU, the generator controller A GCU is used for sensing voltage and current at the circuit breaker APB, and if the reactive power output of the auxiliary generator APU GEN is lower than a third threshold value, the generator controller A GCU executes continuous unfixed power source protection action.

As a preferable configuration of the external power supply phase loss protection structure of the bus bar power controller, the first threshold, the second threshold, and the third threshold are all 0.85.

As a preferred scheme of an external power supply open-phase protection structure of a Bus bar power controller, a Bus bar L235 VAC Bus is connected with a first end of a contactor L ATUC, a second end of the contactor L ATUC is connected with an electric energy conversion device L ATU, the electric energy conversion device L ATU is connected with a first end of a contactor L BSB, and a second end of the contactor L BSB is connected with a Bus bar L115 VAC Bus;

the second end of the contactor L ATUC is connected with the first end of a contactor E1 TRU ISO Rly, the second end of the contactor E1 TRU ISO Rly is respectively connected with the first ends of a power supply conversion device TRU E1 and a contactor E1 TRU Rly, the power supply conversion device TRU E1 is further connected with the first end of a Bus bar ESS 128 VDC Bus, the second end of the contactor ESS ISO Rly is connected with a Bus bar ESS 235VAC Bus, the Bus bar ESS 235VAC Bus is connected with a power supply conversion device TRU 2, and the power supply conversion device TRU E2 is further connected with the Bus bar ESS 228 VDC Bus;

the Bus ESS 128 VDC Bus is connected to a first end of the contactor MBR, and a second end of the contactor MBR is connected to the Bus Hot BB 1;

an external power source L AFT EP is connected with a first end of a contactor L AEPC, and a second end of the contactor L AEPC is connected with an autotransformer rectifier ATRU L.

As an optimal scheme of an external power supply open-phase protection structure of the bus bar power controller, a main generator GEN L supplies power and a main generator GEN R are variable-frequency generators with rated power of 225kVA and rated voltage of 235 VAC; the auxiliary generator APU GEN is a variable frequency generator with rated power of 200kVA and rated voltage of 235 VAC; the generator GEN RAT is a variable frequency generator with rated power of 50kVA and rated voltage of 235 VAC; rated voltages of the ground power supply L FWD EP, the ground power supply R FWD EP and the third external power supply L AFT EP are 115 VAC; rated power of the ATRU L and the ATRU R is 150kVA, rated capacity of the ATU and the ATU is 60kVA, and rated output current of the TRU L, the TRU R, the TRU E1 and the TRU E2 is 240A; the storage battery Main BAT and the storage battery APU BAT are both storage batteries with rated voltage of 28VDC and capacity of 75 Ah.

Compared with the prior art, the invention has the beneficial effects that:

1. introducing 235VAC bus bars to replace the 115VAC bus bars of conventional aircraft, the power rating increases.

2. A 270VDC voltage level was introduced for speed regulation of large motors (air conditioning compressors etc.).

3. The number of external power supply sockets is changed from 1 socket of a traditional airplane to 2, and meanwhile, the voltage class and the capacity of the emergency power supply RAT are increased from the original 115VAC 30kVA to 235VAC 50 kVA.

In addition to the technical problems addressed by the present invention, the technical features constituting the technical solutions, and the advantageous effects brought by the technical features of the technical solutions described above, other technical problems solved by the present invention, other technical features included in the technical solutions, and advantageous effects brought by the technical features will be described in further detail with reference to the accompanying drawings.

Drawings

FIG. 1 shows an external power supply voltage protection information collection point.

Fig. 2 is a power system architecture diagram for a single-channel multi-electric aircraft.

FIG. 3 shows the external power L/R FWD EP over-voltage (OV) protection and reset logic.

FIG. 4 shows the external power L/R FWD EP Undervoltage (UV) protection and reset logic.

FIG. 5 shows the external power L/R FWD EP Phase Sequence (PS) protection and reset logic.

Fig. 6 is an external power Overload (OC) protection information collection point.

FIG. 7 is an external power supply L/R FWD EP Overload (OC) protection control logic.

Fig. 8 is an external power supply L FWD EP bus isolation logic.

Fig. 9 shows external power FWD EP bus isolation logic.

Fig. 10 shows an external power supply frequency protection information collection point.

Fig. 11 is a power system architecture for a single-channel multi-airplane.

Fig. 12 is external power supply over-frequency protection control logic.

Fig. 13 shows external power supply under-frequency protection control logic.

Fig. 14 shows an external power supply open-phase (OP) protection information collection point.

Fig. 15 is a power system architecture for a multi-airplane.

Fig. 16 shows external power supply open-phase (OP) protection control logic.

Detailed Description

The present invention will be described in further detail with reference to the following detailed description and accompanying drawings. The embodiments are described herein to assist understanding of the present invention, but are not to be construed as limiting the present invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example 1:

referring to fig. 1 to 5, the present embodiment relates to a novel external power supply voltage protection structure of a single-channel multi-electric aircraft bus bar power controller. The system comprises a left variable-frequency main starting generator GEN L and a right variable-frequency main starting generator GEN R with the rated power of 225kVA, an APU starting generator with the rated power of 200kVA, and an RAT generator with the rated power of 50 kVA. There are also three external power sources, L FWD EP, R FWD EP and L AFT EP, respectively, the outlets of each of which can support a maximum of 90kVA of power. The rated voltages of the main starter generator, the APU starter generator and the RAT generator are all 235VAC, and the rated voltages of the three external power supplies are 115 VAC. GEN L, GEN R and APU GEN are provided with respective generator breakers L GCB, R GCB and APB to control the switching of the generators, and in addition, the 3 generators are also provided with corresponding contactors L GNR, R GNR and A GNR to control the connection with a ground network. The three external power supplies also have corresponding contactors for controlling the access of the power supplies, namely L EPC, R EPC and L AEPC.

The secondary power supply of the power supply system comprises 2 ATRUs with rated power of 150kVA, two ATUs with rated capacity of 60kVA and 4 TRUs with rated output current of 240A. Wherein, the ATRU converts 235VAC into +/-270VDC, and respectively outputs the +/-270VDC to the left and right buses for supplying power to multi-electrical loads (flight control actuation, electrical ring control and the like); the ATU converts 230VAC into 115VAC, and respectively outputs the 115VAC to the left and right 115VAC bus bars; the TRU converts 235VAC into 28VDC, and outputs the 28VDC normal bus bars and the 28VDC emergency bus bars to the left and right.

The power supply system is provided with two batteries with the rated voltage of 28VDC and the capacity of 75Ah, namely a main battery and an APU battery, and the batteries can supply power for key electronic equipment before the aircraft generator is started. Meanwhile, the APU battery can also be used to start the APU.

Main generator GEN L links to each other with circuit breaker L GCB's first end, and circuit breaker L GCB's second end links to each other with busbar L235 VAC Bus.

The main generator GEN R is connected with the first end of the circuit breaker R GCB, and the second end of the circuit breaker R GCB is connected with the Bus bar R235 VAC Bus.

Auxiliary generator APU GEN links to each other with circuit breaker APB's first end, and busbar L235 VAC Bus links to each other with contactor L BTB's first end, and busbar R235 VAC Bus links to each other with contactor R BTB's first end, and contactor APB's second end links to each other with contactor L BTB's second end and contactor R BTB's second end respectively.

Busbar L235 VAC Bus links to each other with contactor L ATUC's first end, and contactor L ATUC's second end links to each other with electric energy conversion device L ATU, and electric energy conversion device L ATU links to each other with contactor L BSB's first end again, and contactor L BSB's second end links to each other with busbar L115 VAC Bus.

The Bus bar R235 VAC Bus is connected with the first end of the contactor R ATUC, the second end of the contactor R ATUC is connected with the electric energy conversion device R ATU, the electric energy conversion device R ATU is connected with the first end of the contactor R BSB, and the second end of the contactor R BSB is connected with the Bus bar R115 VAC Bus.

Ground power source L FWD EP is connected to a first terminal of contact L EPC, and a second terminal of contact L EPC is connected to a first terminal of contact L BSB.

A ground power supply rwfd EP is connected to a first end of the contactor R EPC, and a second end of the contactor R EPC is connected to a first end of the contactor R BSB.

Bus bar L235 VAC Bus is connected with the first end of contactor LacT, and the second end of contactor LacT is connected with the first end of contactor RacT, and the second end of contactor RacT is connected with Bus bar R235 VAC Bus.

The second end of contactor L ATUC is connected to the first end of contactor L TRU Rly, and the second end of contactor L TRU Rly is connected to power conversion device TRU L, and power conversion device TRU L is connected to busbar L28 VDC Bus again.

The second end of contactor R ATUC links to each other with the first end of contactor R TRU Rly, and the second end of contactor R TRU Rly links to each other with power conversion device TRU R, and power conversion device TRU R links to each other with busbar R28 VDC Bus again.

Bus bar L28 VDC Bus is connected to a first terminal of contact LdcT, a second terminal of contact LdcT is connected to a first terminal of contact RdcT, and a second terminal of contact RdcT is connected to Bus bar R28 VDC Bus.

The second end of the contactor L ATUC is connected to the first end of the contactor E1 TRU ISO Rly, the second end of the contactor E1 TRU ISO Rly is connected to the first ends of the power conversion device TRU E1 and the contactor E1 TRU Rly, respectively, the power conversion device TRU E1 is connected to the first end of the Bus bar ESS 128 VDC Bus, the second end of the contactor ESS ISO Rly is connected to the Bus bar ESS 235VAC Bus, the Bus bar ESS 235VAC Bus is connected to the power conversion device TRU 2, and the power conversion device TRU E2 is connected to the Bus bar ESS 228 VDC Bus.

The generator GEN RAT is connected to a first terminal of a contactor RCB, a second terminal of which is connected to a Bus bar ESS 235VAC Bus.

The Bus ESS 128 VDC Bus is connected to the first terminal of the contact E1T, the second terminal of the contact E1T is connected to the first terminal of the contact E2T, and the second terminal of the contact E2T is connected to the Bus ESS 228 VDC Bus.

The Bus ESS 128 VDC Bus is connected to a first terminal of the contactor MBR, and a second terminal of the contactor MBR is connected to the Bus Hot BB 1.

Busbar Hot BB2 links to each other with contactor SPUC's first end, and contactor SPUC's second end links to each other with the SPU, and the SPU links to each other with contactor SPUB's first end, and contactor SPUB's second end links to each other with self-coupling transformer rectifier ATRU R.

The Bus bar L235 VAC Bus is connected with the first end of the contactor L ATRUC, the second end of the contactor L ATRUC is connected with the autotransformer rectifier ATRU L, and the autotransformer rectifier ATRU L is connected with the Bus bar L270 VDC Bus.

The Bus bar R235 VAC Bus is connected with the first end of the contactor R ATRUC, the second end of the contactor R ATRUC is connected with the autotransformer rectifier ATRU R, and the autotransformer rectifier ATRU R is connected with the Bus bar R270 VDC Bus.

1 external power supply L/R FWD EP Overvoltage (OV) protection

The L/R BPCU collects A, B, C phase voltage corresponding to an external power source L/R FWD EP, a collection point is located on the ground power supply side of the L/R EPC, when the collected highest phase voltage is larger than 122Vrms, Overvoltage (OV) protection is triggered, and the BPCU is disconnected and locks the L/R EPC after the maximum delay of 10 s.

After the highest phase voltage drops below 120Vrms, the external power source L/R FWD EP overvoltage protection trip can be reset by one of three methods:

1) pressing an L/R FWD EXT PWR switch on a control panel of the cockpit;

2) the L/R FWD EP plug of the external power supply on the corresponding socket is unplugged and plugged again;

3) the corresponding BPCU is unplugged and powered up again.

2 external power supply L/R FWD EP Undervoltage (UV) protection

The L/R BPCU collects A, B, C phase voltage corresponding to an L/R FWD EP of an external power supply, a collection point is located on the ground power supply side of the L/R EPC, Undervoltage (UV) protection is triggered when the collected lowest phase voltage is smaller than 100Vrms, and the BPCU is disconnected and locks the L/R EPC after the maximum 9s delay.

The external power supply L/R FWD EP under-voltage protection is suppressed when an Overload (OC) condition is true. The UV conditions of the external power supply L/R FWD EP will simultaneously inhibit the following protections:

1) over-frequency (OF) protection;

2) under-frequency (UF) protection;

3) the BPCU informs the GCU via the Bus to implement UV protection on the L/R235 VAC Bus.

After the lowest phase voltage rises back to be more than 102Vrms, the external power supply L/R FWD EP undervoltage protection trip can be reset by one of the following three methods:

1) pressing an L/R FWD EXT PWR switch on a control panel of the cockpit;

2) unplugging and re-plugging an L/R FWD EP plug of an external power supply on a corresponding socket

3) The corresponding BPCU is powered off and powered back on.

L/R FWD EP Phase Sequence (PS) protection for 3 external power supply

The L/R BPCU collects A, B, C phase voltage corresponding to an external power source L/R FWD EP, the collection point is located on the ground power supply side of the L/R EPC, when the collected voltage phase sequence is not A-B-C, Phase Sequence (PS) protection is triggered, and the BPCU inhibits the closing of the L/R EPC.

When the voltage phase sequence of the FWD EP is restored to a-B-C, the Phase Sequence (PS) protection can be reset by three standard methods:

1) pressing an L/R FWD EXT PWR switch on a control panel of the cockpit;

3) the corresponding BPCU is unplugged and powered up again.

The invention provides an external power supply overload protection function design of a bus bar power controller, which sets a protection threshold value and action time, and how to coordinate with a GCU to complete fault location and isolation.

Example 2:

referring to fig. 6 to 9, the generator includes left and right 2 variable frequency main start generators GEN L and GEN R with a rated power of 225kVA, an APU start generator with a rated power of 200kVA, and a RAT generator with a rated power of 50 kVA. There are also three external power sources, L FWD EP, R FWD EP and L AFT EP, respectively, the outlets of each of which can support a maximum of 90kVA of power. The rated voltages of the main starter generator, the APU starter generator and the RAT generator are all 235VAC, and the rated voltages of the three external power supplies are 115 VAC.

GEN L, GEN R and APU GEN are provided with respective generator breakers L GCB, R GCB and APB to control the switching of the generators, and in addition, the 3 generators are also provided with corresponding contactors L GNR, R GNR and A GNR to control the connection with a ground network.

The three external power supplies also have corresponding contactors for controlling the access of the power supplies, namely L EPC, R EPC and L AEPC.

The secondary power supply of the power supply system comprises 2 ATRUs with rated power of 150kVA, two ATUs with rated capacity of 60kVA and 4 TRUs with rated output current of 240A. Wherein, the ATRU converts 235VAC into +/-270VDC, and respectively outputs the +/-270VDC to the left and right +/-270VDC bus bars for supplying power to multi-electrical loads (flight control actuation, electrical ring control and the like); the ATU converts 230VAC into 115VAC, and respectively outputs the 115VAC to the left and right 115VAC bus bars; the TRU converts 235VAC into 28VDC, and outputs the 28VDC normal bus bars and the 28VDC emergency bus bars to the left and right.

Compared with a multi-electric airplane, the power supply system of the traditional airplane is much simpler in structure. The conventional aircraft has a generator bus of 115VAC, thus eliminating the need for a 235VAC to 115VAC electrical power conversion unit ATU, and eliminating the need for a 235VAC to 270VDC electrical power conversion unit ATRU.

In addition, the power system architecture of a multi-electric aircraft has multiple external power sources, while a traditional aircraft has only one way. Special considerations are therefore taken when setting the overload protection logic and fault isolation measures.

An Overload (OC) information acquisition point and a control point of the BPCU to the L/R FWD EP of the external power supply. The information acquisition and control points in the diagram are more, and the acquisition of three-phase current of an L/R EPC feeder line and the acquisition of contactor states (EPC, BSB, LacT and RacT) are involved, and meanwhile, the acquisition of the three-phase current of the L/R EPC feeder line and the acquisition of the contactor states (EPC, BSB, LacT and RacT) are matched with a GCU (general packet radio terminal) to complete power grid reconstruction under the condition of faults.

1 external power supply L/R FWD EP Overload (OC) protection

The L/R BPCU collects A, B, C three-phase current of the L/R FWD EP, and a collection point is located on a feeder line of the L/R EPC contactor close to the side of the ground power supply vehicle. The purpose of over-load (OC) protection is to make the L/R FWD EP supply as much as possible to the respective 115VAC and 235VAC bus bars. Whether power is supplied can be judged by detecting whether the L/L BSB on the side or the R/L BSB on the opposite side is closed.

When the BPCU detects that the current of the highest phase of the L/R FWD EP is greater than or equal to 270A for 300s (OC 1), or greater than 326A for 5.2s (OC 2), it opens and blocks the associated L/R FWD EPC, L/R BSB, LacT, RacT, and L/R ATUC.

The BPCU will open the contactors to locate and locate the fault according to the programmed settings and once the fault area is located, the contactors will reclose to power those bus bars that are not faulty.

The time delay of the L/R FWD EP OC1 is reset after the highest phase current has fallen to 250A, and the time delay of the L/R FWD EP OC2 is reset after the highest phase current has fallen to 306A.

2 external power supply LFWD EP bus isolation

Upon occurrence of the L FWD EP OC fault condition, the L BPCU sends an ATUC trip request to the L GCU via the communication bus, and the corresponding L GCU will open and latch L ATUC in response to this command request. If the fault is still present after 100ms, the L BPCU will open and latch the L BSB, while an OC BSB protection trip request is sent to the R BPCU over the communication bus, leaving the R BPCU open and latching the L BSB.

And if the fault disappears after the L BSB is disconnected, the L BPCU disconnects and locks the LacT, and simultaneously sends an ATUC OC protection reset request to the L GCU to request the L GCU to reclose the L ATUC.

If the fault still exists after the L BSB is disconnected for 100ms, the L BPCU can open and lock the L EPC. At this time, L ATUC and LacT maintain the open and locked state.

The L BPCU and the R BPCU control contactor L BSB simultaneously, where L BPCU is the master and R BPCU is the slave. The closing of the L BSB contactor can be controlled by only one BPCU, and the main contact is closed as long as one BPCU supplies excitation current to the coil of the L BSB; to turn off the L BSB, it is necessary to turn off the excitation current of the contactor coil simultaneously with the L BPCU and the R BPCU.

3 external power RFWD EP bus isolation

Upon occurrence of the R FWD EP OC fault condition, the R BPCU sends an ATUC trip request to the R GCU via the communication bus, and the corresponding R GCU will open and latch R ATUC in response to this command request. If the fault is still present after 100ms, the R BPCU will open and latch the R BSB, while an OC BSB protection trip request is sent to the L BPCU through the communication bus, leaving the L BPCU open and latch the R BSB.

And if the fault disappears after the R BSB is disconnected, the R BPCU is disconnected and locks the RacT, and simultaneously sends an ATUC OC protection reset request to the R GCU to request the R GCU to reclose the R ATUC.

If the fault still exists after the R BSB is disconnected for 100ms, the R BPCU can be disconnected and lock the R EPC. At this time, R ATUC and RacT maintain the open and locked state.

Example 3:

referring to fig. 10 to 13, the power supply system of a single-channel multi-electric aircraft includes left and right 2 variable-frequency main starter generators GEN L and GEN R rated at 225kVA, an APU starter generator rated at 200kVA, and a RAT generator rated at 50 kVA. There are also three external power sources, L FWD EP, R FWD EP and L AFT EP, respectively, the outlets of each of which can support a maximum of 90kVA of power. The rated voltages of the main starter generator, the APU starter generator and the RAT generator are all 235VAC, and the rated voltages of the three external power sources are 115 VAC.

The power supply system has two batteries with the rated voltage of 28VDC and the capacity of 75Ah, namely a main battery and an APU battery, and the batteries can supply power to key electronic equipment before the aircraft generator is started. Meanwhile, the APU battery can also be used to start the APU.

the second end of the contactor R ATUC is connected with the first end of the contactor R TRU Rly, the second end of the contactor R TRU Rly is connected with the power supply conversion device TRU R, and the power supply conversion device TRU R is connected with the Bus bar R28 VDC Bus;

1 over-frequency (OF) protection OF an external power source L/R FWD EP

The L/R BPCU collects the frequency corresponding to the L/R FWD EP A phase, and the collection point is located at the end of the L/R EPC close to the ground power supply side. The BPCU will filter the frequency of the acquisition point to eliminate noise from the ground power cart.

When the L/R FWD EP UV condition is met, L/R FWD EP OF protection is inhibited.

1) pressing an L/R FWD EXT PWR switch on a control panel of the cockpit;

3) the corresponding BPCU is unplugged and powered up again.

2 under-frequency (UF) protection of external power L/R FWD EP

The L/R BPCU collects the frequency corresponding to the L/R FWD EP A phase, and the collection point is located at the end of the L/R EPC close to the ground power supply side. The BPCU filters the frequency of the acquisition points to eliminate noise from the ground power cart.

When the L/R FWD EP UV condition is met, L/R FWD EP UF protection will be inhibited.

1) pressing an L/R FWD EXT PWR switch on a control panel of the cockpit;

3) the corresponding BPCU is unplugged and powered up again.

Example 4:

referring to fig. 14 to 16, the present embodiment relates to a novel external power supply open-phase protection structure of a single-channel multi-electrical aircraft bus bar power controller. The system comprises a left variable-frequency main starting generator GEN L and a right variable-frequency main starting generator GEN R with the rated power of 225kVA, an APU starting generator with the rated power of 200kVA, and an RAT generator with the rated power of 50 kVA. There are also three external power sources, L FWD EP, R FWD EP and L AFT EP, respectively, the outlets of each of which can support a maximum of 90kVA of power. The rated voltages of the main starter generator, the APU starter generator and the RAT generator are all 235VAC, and the rated voltages of the three external power supplies are 115 VAC. GEN L, GEN R and APU GEN are provided with respective generator breakers L GCB, R GCB and APB to control the switching of the generators, and in addition, the 3 generators are also provided with corresponding contactors L GNR, R GNR and A GNR to control the connection with a ground network. The three external power supplies also have corresponding contactors for controlling the access of the power supplies, namely L EPC, R EPC and L AEPC.

The main generator GEN L is connected with the first end of the circuit breaker L GCB, and the second end of the circuit breaker L GCB is connected with the Bus bar L235 VAC Bus.

Busbar R235 VAC Bus links to each other with contactor R ATUC's first end, and contactor R ATUC's second end links to each other with electric energy conversion device R ATU, and electric energy conversion device R ATU links to each other with contactor R BSB's first end again, and contactor R BSB's second end links to each other with busbar R115 VAC Bus.

The second end of the contactor L ATUC is connected to the first end of the contactor L TRU Rly, the second end of the contactor L TRU Rly is connected to the power conversion device TRU L, which is connected to the Bus bar L28 VDC Bus.

The generator GEN RAT is connected to a first end of a contactor RCB, the second end of which is connected to a Bus bar ESS 235VAC Bus.

Bus ESS 128 VDC Bus is connected to a first terminal of contactor MBR, and a second terminal of contactor MBR is connected to Bus Hot BB 1.

The bus bar Hot BB2 is connected with a first end of a contactor SPUC, a second end of the contactor SPUC is connected with an SPU, the SPU is connected with a first end of a contactor SPUB, and a second end of the contactor SPUB is connected with an ATRU R.

The L/R BPCU can collect A, B, C three-phase current of the L/R FWD EP, and a collection point is located on a feeder line of an L/R EPC contactor close to a ground power supply vehicle. And if the current of the lowest phase of the L/R FWD EP is less than 11A, and the difference between the current of the next lowest phase and the current of the lowest phase is more than 55A, determining that the L/R FWD EP is in a phase-missing (OP) condition.

The BPCU will open and latch the L/R EPC within 4s after the open phase condition is met.

In the presence of an Overload (OC) condition in the L/R FWD EP, the L/R FWD OP protection is suppressed.

Open phase protection is used to determine whether a phase load has been disconnected from the neutral point of the L/R FWD EP.

When the lowest phase current is greater than 20A or the difference between the next lowest phase current and the lowest phase current is less than 45A, the L/R FWD EP OP protection can be reset by pressing the L/R FWD EXT PWR at the cockpit control panel.

The L/R FWD EP OP protection does not act in the event of a failure of the main AC bus or the downstream AC bus.

The foregoing merely represents embodiments of the present invention, which are described in some detail and detail, and therefore should not be construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The external power voltage protection structure of bus bar power controller is characterized by comprising,

the ground power supply L FWD EP is connected with a first end of a contactor L EPC, and a second end of the contactor L EPC is connected with a first end of a contactor L BSB;

the voltage protection functions include overvoltage OV protection, undervoltage UV protection, and phase sequence PS protection.

2. The overload protection structure of external power source for bus bar power controller is characterized by that it includes,

the second end of the contactor L ATUC is connected with the first end of the contactor L TRU Rly, the second end of the contactor L TRU Rly is connected with a power supply conversion device TRU L, and the power supply conversion device TRU L is connected with a Bus bar L28 VDC Bus;

3. The external power frequency protection structure of bus bar power controller is characterized by comprising,

4. The external power supply frequency protection structure of a bus bar power controller according to claim 3,

when the acquired frequency is larger than or equal to 410Hz, the over-frequency OF protection OF the BPCU acts, and the L/R FWD EPC is disconnected and locked;

when the L/R FWD EP UV condition is met, L/R FWD EP OF protection is inhibited;

when the L/R FWD EP A phase frequency drops below 409Hz, the L/R FWD EP OF trip protection is reset by one OF the three standard methods:

1) pressing an L/R FWD EXT PWR switch on a control panel of the cockpit;

3) unplugging the power supply of the corresponding BPCU and powering up again;

when the acquired frequency is less than or equal to 390Hz, the under-frequency UF protection of the BPCU can act, and the L/R FWD EPC can be disconnected and locked;

when the L/R FWD EP UV condition is met, L/R FWD EP UF protection will be inhibited;

when the L/R FWD EP A phase frequency rises back above 391Hz, the L/R FWD EP UF protection trip is reset by one of three standard methods:

1) pressing an L/R FWD EXT PWR switch on a control panel of the cockpit;

3) the corresponding BPCU is unplugged and powered up again.

5. An external power supply open-phase protection structure of a bus power controller is characterized by comprising,

the L/R BPCU collects A, B, C three-phase current of the L/R FWD EP, and a collection point is located on a feeder line of the L/R EPC contactor close to the ground power supply side.