High-Voltage Heater Voltage Sensing for Open Heating Unit Detection

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Solution Overview

Problem

Existing high-voltage heaters, particularly those in electric vehicles, face challenges in detecting disconnection of heating units when the system is not operating, leading to potential burnout or damage due to the inability to detect disconnections outside of operational states.

Innovation Solution

A high-voltage heater with a disconnection detection unit that checks voltage between the heating unit and switching unit, even when the system is not powered, using a disconnection detection method involving a control unit, high-voltage detection, and pulse width modulation signals to determine disconnection and restrict operation to prevent damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If disconnection detection is performed using current magnitude during operation, then disconnection can be detected when the heater operates, but disconnection cannot be detected when the heater does not operate or power is not supplied

Engineering Contradiction:

Improvedisconnection detection capabilityVSAvoiddetection coverage across operational states

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by performing disconnection detection before the heater operates. The control unit detects voltage between the heating unit and switching unit in a non-operational state (when PWM signal is not output), allowing disconnection to be identified before it causes damage during operation. This preventive detection expands coverage to include non-operational states.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent inverts the detection approach by measuring voltage instead of current. Rather than detecting current flow during operation, the system detects voltage presence in non-operational state. When high voltage is applied and PWM is not output, a normal heating unit should show voltage between it and the switching unit, while a disconnected unit shows no voltage, enabling detection through this inverted measurement paradigm.

Inventive Principle:

Principle #13The other way round (Inversion)

2Productivity

If multiple heating units are connected in parallel to improve heating performance, then heating capacity increases, but the risk of undetected disconnection and subsequent damage increases

Engineering Contradiction:

Improveheating performanceVSAvoidburnout and damage risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by continuously monitoring voltage conditions and providing information to the control unit. When disconnection is detected through voltage measurement, the control unit receives feedback and restricts PWM output, preventing operation with disconnected heating units and eliminating the harmful effects of burnout and damage.

Inventive Principle:

Principle #23Feedback

3Reliability

If voltage detection method is used to detect disconnection in non-operational state, then detection coverage is improved, but system complexity increases due to additional detection circuitry

Engineering Contradiction:

Improvedetection coverageVSAvoiddetection system structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by making the voltage detection mechanism serve multiple functions. The same voltage detection circuitry used for disconnection detection also provides information about the operational state of the heater. By detecting voltage between the heating unit and switching unit, the system simultaneously determines both disconnection status and operational readiness, reducing the need for separate detection systems.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent applies self-service by using the existing high voltage supply and circuit components for detection purposes. The system uses the applied high voltage itself as the detection signal source, and the existing switching unit and heating unit structure provides the detection pathway. This eliminates the need for external detection equipment or additional power sources, keeping the system simple despite enhanced detection capability.

Inventive Principle:

Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables detection of heating unit disconnections before or after operation, preventing burnout and damage by restricting operation when disconnections are detected, and reduces costs through the use of inexpensive components, improving detection accuracy compared to software-based methods.

Implementation Method 1

a heating unit provided between the switching unit and the high-voltage supply unit on the high-voltage line and configured to generate heat under the control of the switching unit

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentUS20230406068A1High-voltage heater including disconnection detection unit and disconnection detection method using same

Publication Date: 2023.12.21 HANON SYST CO LTD

AI summary

The present invention relates to a high-voltage heater that generates heat by using a heating effect of an electric current, and more particularly, to a high-voltage heater including a disconnection detection unit, which is capable of detecting disconnection of a heating unit by checking a voltage between the heating unit and a switching unit when a high voltage is applied even in a state in which a heater does not operate, and a disconnection detection method using the same.